/*
 * Copyright (c) 2021, Alliance for Open Media. All rights reserved
 *
 * This source code is subject to the terms of the BSD 3-Clause Clear License
 * and the Alliance for Open Media Patent License 1.0. If the BSD 3-Clause Clear
 * License was not distributed with this source code in the LICENSE file, you
 * can obtain it at aomedia.org/license/software-license/bsd-3-c-c/.  If the
 * Alliance for Open Media Patent License 1.0 was not distributed with this
 * source code in the PATENTS file, you can obtain it at
 * aomedia.org/license/patent-license/.
 */

#include <assert.h>
#include <immintrin.h>

#include "config/aom_config.h"

#include "aom_ports/mem.h"
#include "aom/aom_integer.h"

#include "aom_dsp/aom_dsp_common.h"
#include "aom_dsp/x86/obmc_intrinsic_ssse3.h"
#include "aom_dsp/x86/synonyms.h"

////////////////////////////////////////////////////////////////////////////////
// High bit-depth
////////////////////////////////////////////////////////////////////////////////

static INLINE unsigned int hbd_obmc_sad_w4_avx2(const uint8_t *pre8,
                                                const int pre_stride,
                                                const int32_t *wsrc,
                                                const int32_t *mask,
                                                const int height) {
  const uint16_t *pre = CONVERT_TO_SHORTPTR(pre8);
  int n = 0;
  __m256i v_sad_d = _mm256_setzero_si256();
  const __m256i v_bias_d = _mm256_set1_epi32((1 << 12) >> 1);
  do {
    const __m128i v_p_w_0 = xx_loadl_64(pre);
    const __m128i v_p_w_1 = xx_loadl_64(pre + pre_stride);
    const __m128i v_p_w = _mm_unpacklo_epi64(v_p_w_0, v_p_w_1);
    const __m256i v_m_d = _mm256_lddqu_si256((__m256i *)(mask + n));
    const __m256i v_w_d = _mm256_lddqu_si256((__m256i *)(wsrc + n));

    const __m256i v_p_d = _mm256_cvtepu16_epi32(v_p_w);

    // Values in both pre and mask fit in 15 bits, and are packed at 32 bit
    // boundaries. We use pmaddwd, as it has lower latency on Haswell
    // than pmulld but produces the same result with these inputs.
    const __m256i v_pm_d = _mm256_madd_epi16(v_p_d, v_m_d);

    const __m256i v_diff_d = _mm256_sub_epi32(v_w_d, v_pm_d);
    const __m256i v_absdiff_d = _mm256_abs_epi32(v_diff_d);

    // Rounded absolute difference

    const __m256i v_tmp_d = _mm256_add_epi32(v_absdiff_d, v_bias_d);
    const __m256i v_rad_d = _mm256_srli_epi32(v_tmp_d, 12);

    v_sad_d = _mm256_add_epi32(v_sad_d, v_rad_d);

    n += 8;

    pre += pre_stride << 1;
  } while (n < 8 * (height >> 1));

  __m128i v_sad_d_0 = _mm256_castsi256_si128(v_sad_d);
  __m128i v_sad_d_1 = _mm256_extracti128_si256(v_sad_d, 1);
  v_sad_d_0 = _mm_add_epi32(v_sad_d_0, v_sad_d_1);
  return xx_hsum_epi32_si32(v_sad_d_0);
}

static INLINE unsigned int hbd_obmc_sad_w8n_avx2(
    const uint8_t *pre8, const int pre_stride, const int32_t *wsrc,
    const int32_t *mask, const int width, const int height) {
  const uint16_t *pre = CONVERT_TO_SHORTPTR(pre8);
  const int pre_step = pre_stride - width;
  int n = 0;
  __m256i v_sad_d = _mm256_setzero_si256();
  const __m256i v_bias_d = _mm256_set1_epi32((1 << 12) >> 1);

  assert(width >= 8);
  assert(IS_POWER_OF_TWO(width));

  do {
    const __m128i v_p0_w = _mm_lddqu_si128((__m128i *)(pre + n));
    const __m256i v_m0_d = _mm256_lddqu_si256((__m256i *)(mask + n));
    const __m256i v_w0_d = _mm256_lddqu_si256((__m256i *)(wsrc + n));

    const __m256i v_p0_d = _mm256_cvtepu16_epi32(v_p0_w);

    // Values in both pre and mask fit in 15 bits, and are packed at 32 bit
    // boundaries. We use pmaddwd, as it has lower latency on Haswell
    // than pmulld but produces the same result with these inputs.
    const __m256i v_pm0_d = _mm256_madd_epi16(v_p0_d, v_m0_d);

    const __m256i v_diff0_d = _mm256_sub_epi32(v_w0_d, v_pm0_d);
    const __m256i v_absdiff0_d = _mm256_abs_epi32(v_diff0_d);

    // Rounded absolute difference
    const __m256i v_tmp_d = _mm256_add_epi32(v_absdiff0_d, v_bias_d);
    const __m256i v_rad0_d = _mm256_srli_epi32(v_tmp_d, 12);

    v_sad_d = _mm256_add_epi32(v_sad_d, v_rad0_d);

    n += 8;

    if (n % width == 0) pre += pre_step;
  } while (n < width * height);

  __m128i v_sad_d_0 = _mm256_castsi256_si128(v_sad_d);
  __m128i v_sad_d_1 = _mm256_extracti128_si256(v_sad_d, 1);
  v_sad_d_0 = _mm_add_epi32(v_sad_d_0, v_sad_d_1);
  return xx_hsum_epi32_si32(v_sad_d_0);
}

#define HBD_OBMCSADWXH(w, h)                                           \
  unsigned int aom_highbd_obmc_sad##w##x##h##_avx2(                    \
      const uint8_t *pre, int pre_stride, const int32_t *wsrc,         \
      const int32_t *mask) {                                           \
    if (w == 4) {                                                      \
      return hbd_obmc_sad_w4_avx2(pre, pre_stride, wsrc, mask, h);     \
    } else {                                                           \
      return hbd_obmc_sad_w8n_avx2(pre, pre_stride, wsrc, mask, w, h); \
    }                                                                  \
  }

HBD_OBMCSADWXH(128, 128)
HBD_OBMCSADWXH(128, 64)
HBD_OBMCSADWXH(64, 128)
HBD_OBMCSADWXH(64, 64)
HBD_OBMCSADWXH(64, 32)
HBD_OBMCSADWXH(32, 64)
HBD_OBMCSADWXH(32, 32)
HBD_OBMCSADWXH(32, 16)
HBD_OBMCSADWXH(16, 32)
HBD_OBMCSADWXH(16, 16)
HBD_OBMCSADWXH(16, 8)
HBD_OBMCSADWXH(8, 16)
HBD_OBMCSADWXH(8, 8)
HBD_OBMCSADWXH(8, 4)
HBD_OBMCSADWXH(4, 8)
HBD_OBMCSADWXH(4, 4)
HBD_OBMCSADWXH(4, 16)
HBD_OBMCSADWXH(16, 4)
HBD_OBMCSADWXH(8, 32)
HBD_OBMCSADWXH(32, 8)
HBD_OBMCSADWXH(16, 64)
HBD_OBMCSADWXH(64, 16)