/*
 * Copyright (c) 2018, Alliance for Open Media. All rights reserved
 *
 * This source code is subject to the terms of the BSD 2 Clause License and
 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
 * was not distributed with this source code in the LICENSE file, you can
 * obtain it at www.aomedia.org/license/software. 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 www.aomedia.org/license/patent.
 */

#include <immintrin.h>

#include "config/aom_dsp_rtcd.h"

#include "aom_dsp/x86/convolve_avx2.h"
#include "aom_dsp/x86/convolve_common_intrin.h"
#include "aom_dsp/x86/convolve_sse4_1.h"
#include "aom_dsp/aom_dsp_common.h"
#include "aom_dsp/aom_filter.h"
#include "av1/common/convolve.h"

static INLINE __m256i unpack_weights_avx2(ConvolveParams *conv_params) {
  const int w0 = conv_params->fwd_offset;
  const int w1 = conv_params->bck_offset;
  const __m256i wt0 = _mm256_set1_epi16(w0);
  const __m256i wt1 = _mm256_set1_epi16(w1);
  const __m256i wt = _mm256_unpacklo_epi16(wt0, wt1);
  return wt;
}

static INLINE __m256i load_line2_avx2(const void *a, const void *b) {
  return _mm256_permute2x128_si256(
      _mm256_castsi128_si256(_mm_loadu_si128((__m128i *)a)),
      _mm256_castsi128_si256(_mm_loadu_si128((__m128i *)b)), 0x20);
}

void av1_dist_wtd_convolve_x_avx2(const uint8_t *src, int src_stride,
                                  uint8_t *dst0, int dst_stride0, int w, int h,
                                  const InterpFilterParams *filter_params_x,
                                  const InterpFilterParams *filter_params_y,
                                  const int subpel_x_q4, const int subpel_y_q4,
                                  ConvolveParams *conv_params) {
  CONV_BUF_TYPE *dst = conv_params->dst;
  int dst_stride = conv_params->dst_stride;
  const int bd = 8;
  int i, j;
  const int fo_horiz = filter_params_x->taps / 2 - 1;
  const uint8_t *const src_ptr = src - fo_horiz;
  const int bits = FILTER_BITS - conv_params->round_1;
  const __m256i wt = unpack_weights_avx2(conv_params);
  const int do_average = conv_params->do_average;
  const int use_dist_wtd_comp_avg = conv_params->use_dist_wtd_comp_avg;
  const int offset_0 =
      bd + 2 * FILTER_BITS - conv_params->round_0 - conv_params->round_1;
  const int offset = (1 << offset_0) + (1 << (offset_0 - 1));
  const __m256i offset_const = _mm256_set1_epi16(offset);
  const int rounding_shift =
      2 * FILTER_BITS - conv_params->round_0 - conv_params->round_1;
  const __m256i rounding_const = _mm256_set1_epi16((1 << rounding_shift) >> 1);
  __m256i filt[4], coeffs[4];

  assert(bits >= 0);
  assert(conv_params->round_0 > 0);

  filt[0] = _mm256_load_si256((__m256i const *)filt_global_avx2);
  filt[1] = _mm256_load_si256((__m256i const *)(filt_global_avx2 + 32));
  filt[2] = _mm256_load_si256((__m256i const *)(filt_global_avx2 + 32 * 2));
  filt[3] = _mm256_load_si256((__m256i const *)(filt_global_avx2 + 32 * 3));

  prepare_coeffs_lowbd(filter_params_x, subpel_x_q4, coeffs);

  const __m256i round_const =
      _mm256_set1_epi16((1 << (conv_params->round_0 - 1)) >> 1);
  const __m128i round_shift = _mm_cvtsi32_si128(conv_params->round_0 - 1);

  (void)filter_params_y;
  (void)subpel_y_q4;

  for (i = 0; i < h; i += 2) {
    const uint8_t *src_data = src_ptr + i * src_stride;
    CONV_BUF_TYPE *dst_data = dst + i * dst_stride;
    for (j = 0; j < w; j += 8) {
      const __m256i data =
          load_line2_avx2(&src_data[j], &src_data[j + src_stride]);

      __m256i res = convolve_lowbd_x(data, coeffs, filt);

      res = _mm256_sra_epi16(_mm256_add_epi16(res, round_const), round_shift);

      res = _mm256_slli_epi16(res, bits);

      const __m256i res_unsigned = _mm256_add_epi16(res, offset_const);

      // Accumulate values into the destination buffer
      if (do_average) {
        const __m256i data_ref_0 =
            load_line2_avx2(&dst_data[j], &dst_data[j + dst_stride]);
        const __m256i comp_avg_res =
            comp_avg(&data_ref_0, &res_unsigned, &wt, use_dist_wtd_comp_avg);

        const __m256i round_result = convolve_rounding(
            &comp_avg_res, &offset_const, &rounding_const, rounding_shift);

        const __m256i res_8 = _mm256_packus_epi16(round_result, round_result);
        const __m128i res_0 = _mm256_castsi256_si128(res_8);
        const __m128i res_1 = _mm256_extracti128_si256(res_8, 1);

        if (w > 4) {
          _mm_storel_epi64((__m128i *)(&dst0[i * dst_stride0 + j]), res_0);
          _mm_storel_epi64(
              (__m128i *)((&dst0[i * dst_stride0 + j + dst_stride0])), res_1);
        } else {
          *(uint32_t *)(&dst0[i * dst_stride0 + j]) = _mm_cvtsi128_si32(res_0);
          *(uint32_t *)(&dst0[i * dst_stride0 + j + dst_stride0]) =
              _mm_cvtsi128_si32(res_1);
        }
      } else {
        const __m128i res_0 = _mm256_castsi256_si128(res_unsigned);
        _mm_store_si128((__m128i *)(&dst[i * dst_stride + j]), res_0);

        const __m128i res_1 = _mm256_extracti128_si256(res_unsigned, 1);
        _mm_store_si128((__m128i *)(&dst[i * dst_stride + j + dst_stride]),
                        res_1);
      }
    }
  }
}

void av1_dist_wtd_convolve_y_avx2(const uint8_t *src, int src_stride,
                                  uint8_t *dst0, int dst_stride0, int w, int h,
                                  const InterpFilterParams *filter_params_x,
                                  const InterpFilterParams *filter_params_y,
                                  const int subpel_x_q4, const int subpel_y_q4,
                                  ConvolveParams *conv_params) {
  CONV_BUF_TYPE *dst = conv_params->dst;
  int dst_stride = conv_params->dst_stride;
  const int bd = 8;
  int i, j;
  const int fo_vert = filter_params_y->taps / 2 - 1;
  const uint8_t *const src_ptr = src - fo_vert * src_stride;
  // +1 to compensate for dividing the filter coeffs by 2
  const int left_shift = FILTER_BITS - conv_params->round_0 + 1;
  const __m256i round_const =
      _mm256_set1_epi32((1 << conv_params->round_1) >> 1);
  const __m128i round_shift = _mm_cvtsi32_si128(conv_params->round_1);
  const __m256i wt = unpack_weights_avx2(conv_params);
  const int do_average = conv_params->do_average;
  const int use_dist_wtd_comp_avg = conv_params->use_dist_wtd_comp_avg;
  const int offset_0 =
      bd + 2 * FILTER_BITS - conv_params->round_0 - conv_params->round_1;
  const int offset = (1 << offset_0) + (1 << (offset_0 - 1));
  const __m256i offset_const = _mm256_set1_epi16(offset);
  const int offset_1 = (1 << (bd + FILTER_BITS - 2));
  const __m256i offset_const_1 = _mm256_set1_epi16(offset_1);
  const __m256i offset_const_2 = _mm256_set1_epi16((1 << offset_0));
  const int rounding_shift =
      2 * FILTER_BITS - conv_params->round_0 - conv_params->round_1;
  const __m256i rounding_const = _mm256_set1_epi16((1 << rounding_shift) >> 1);
  const __m256i zero = _mm256_setzero_si256();
  __m256i coeffs[4], s[8];

  assert((FILTER_BITS - conv_params->round_0) >= 0);

  prepare_coeffs_lowbd(filter_params_y, subpel_y_q4, coeffs);

  (void)conv_params;
  (void)filter_params_x;
  (void)subpel_x_q4;

  for (j = 0; j < w; j += 16) {
    const uint8_t *data = &src_ptr[j];
    __m256i src6;
    // Load lines a and b. Line a to lower 128, line b to upper 128
    {
      __m256i src_ab[7];
      __m256i src_a[7];
      src_a[0] = _mm256_castsi128_si256(_mm_loadu_si128((__m128i *)data));
      for (int kk = 0; kk < 6; ++kk) {
        data += src_stride;
        src_a[kk + 1] =
            _mm256_castsi128_si256(_mm_loadu_si128((__m128i *)data));
        src_ab[kk] = _mm256_permute2x128_si256(src_a[kk], src_a[kk + 1], 0x20);
      }
      src6 = src_a[6];
      s[0] = _mm256_unpacklo_epi8(src_ab[0], src_ab[1]);
      s[1] = _mm256_unpacklo_epi8(src_ab[2], src_ab[3]);
      s[2] = _mm256_unpacklo_epi8(src_ab[4], src_ab[5]);
      s[4] = _mm256_unpackhi_epi8(src_ab[0], src_ab[1]);
      s[5] = _mm256_unpackhi_epi8(src_ab[2], src_ab[3]);
      s[6] = _mm256_unpackhi_epi8(src_ab[4], src_ab[5]);
    }

    for (i = 0; i < h; i += 2) {
      data = &src_ptr[(i + 7) * src_stride + j];
      const __m256i src7 =
          _mm256_castsi128_si256(_mm_loadu_si128((__m128i *)data));
      const __m256i src_67a = _mm256_permute2x128_si256(src6, src7, 0x20);

      src6 = _mm256_castsi128_si256(
          _mm_loadu_si128((__m128i *)(data + src_stride)));
      const __m256i src_78a = _mm256_permute2x128_si256(src7, src6, 0x20);

      s[3] = _mm256_unpacklo_epi8(src_67a, src_78a);
      s[7] = _mm256_unpackhi_epi8(src_67a, src_78a);

      __m256i res_lo = convolve_lowbd(s, coeffs);

      res_lo = _mm256_add_epi16(res_lo, offset_const_1);

      const __m256i res_lo_0_32b = _mm256_unpacklo_epi16(res_lo, zero);
      const __m256i res_lo_0_shift =
          _mm256_slli_epi32(res_lo_0_32b, left_shift);
      const __m256i res_lo_0_round = _mm256_sra_epi32(
          _mm256_add_epi32(res_lo_0_shift, round_const), round_shift);

      const __m256i res_lo_1_32b = _mm256_unpackhi_epi16(res_lo, zero);
      const __m256i res_lo_1_shift =
          _mm256_slli_epi32(res_lo_1_32b, left_shift);
      const __m256i res_lo_1_round = _mm256_sra_epi32(
          _mm256_add_epi32(res_lo_1_shift, round_const), round_shift);

      const __m256i res_lo_round =
          _mm256_packs_epi32(res_lo_0_round, res_lo_1_round);

      const __m256i res_lo_unsigned =
          _mm256_add_epi16(res_lo_round, offset_const_2);

      if (w - j < 16) {
        if (do_average) {
          const __m256i data_ref_0 = load_line2_avx2(
              &dst[i * dst_stride + j], &dst[i * dst_stride + j + dst_stride]);
          const __m256i comp_avg_res = comp_avg(&data_ref_0, &res_lo_unsigned,
                                                &wt, use_dist_wtd_comp_avg);

          const __m256i round_result = convolve_rounding(
              &comp_avg_res, &offset_const, &rounding_const, rounding_shift);

          const __m256i res_8 = _mm256_packus_epi16(round_result, round_result);
          const __m128i res_0 = _mm256_castsi256_si128(res_8);
          const __m128i res_1 = _mm256_extracti128_si256(res_8, 1);

          if (w - j > 4) {
            _mm_storel_epi64((__m128i *)(&dst0[i * dst_stride0 + j]), res_0);
            _mm_storel_epi64(
                (__m128i *)((&dst0[i * dst_stride0 + j + dst_stride0])), res_1);
          } else {
            *(uint32_t *)(&dst0[i * dst_stride0 + j]) =
                _mm_cvtsi128_si32(res_0);
            *(uint32_t *)(&dst0[i * dst_stride0 + j + dst_stride0]) =
                _mm_cvtsi128_si32(res_1);
          }
        } else {
          const __m128i res_0 = _mm256_castsi256_si128(res_lo_unsigned);
          _mm_store_si128((__m128i *)(&dst[i * dst_stride + j]), res_0);

          const __m128i res_1 = _mm256_extracti128_si256(res_lo_unsigned, 1);
          _mm_store_si128((__m128i *)(&dst[i * dst_stride + j + dst_stride]),
                          res_1);
        }
      } else {
        __m256i res_hi = convolve_lowbd(s + 4, coeffs);

        res_hi = _mm256_add_epi16(res_hi, offset_const_1);

        const __m256i res_hi_0_32b = _mm256_unpacklo_epi16(res_hi, zero);
        const __m256i res_hi_0_shift =
            _mm256_slli_epi32(res_hi_0_32b, left_shift);
        const __m256i res_hi_0_round = _mm256_sra_epi32(
            _mm256_add_epi32(res_hi_0_shift, round_const), round_shift);

        const __m256i res_hi_1_32b = _mm256_unpackhi_epi16(res_hi, zero);
        const __m256i res_hi_1_shift =
            _mm256_slli_epi32(res_hi_1_32b, left_shift);
        const __m256i res_hi_1_round = _mm256_sra_epi32(
            _mm256_add_epi32(res_hi_1_shift, round_const), round_shift);

        const __m256i res_hi_round =
            _mm256_packs_epi32(res_hi_0_round, res_hi_1_round);

        const __m256i res_hi_unsigned =
            _mm256_add_epi16(res_hi_round, offset_const_2);

        if (do_average) {
          const __m256i data_ref_0_lo = load_line2_avx2(
              &dst[i * dst_stride + j], &dst[i * dst_stride + j + dst_stride]);

          const __m256i data_ref_0_hi =
              load_line2_avx2(&dst[i * dst_stride + j + 8],
                              &dst[i * dst_stride + j + 8 + dst_stride]);

          const __m256i comp_avg_res_lo = comp_avg(
              &data_ref_0_lo, &res_lo_unsigned, &wt, use_dist_wtd_comp_avg);

          const __m256i comp_avg_res_hi = comp_avg(
              &data_ref_0_hi, &res_hi_unsigned, &wt, use_dist_wtd_comp_avg);

          const __m256i round_result_lo = convolve_rounding(
              &comp_avg_res_lo, &offset_const, &rounding_const, rounding_shift);

          const __m256i round_result_hi = convolve_rounding(
              &comp_avg_res_hi, &offset_const, &rounding_const, rounding_shift);

          const __m256i res_8 =
              _mm256_packus_epi16(round_result_lo, round_result_hi);
          const __m128i res_0 = _mm256_castsi256_si128(res_8);
          const __m128i res_1 = _mm256_extracti128_si256(res_8, 1);

          _mm_store_si128((__m128i *)(&dst0[i * dst_stride0 + j]), res_0);
          _mm_store_si128(
              (__m128i *)((&dst0[i * dst_stride0 + j + dst_stride0])), res_1);

        } else {
          const __m128i res_lo_0 = _mm256_castsi256_si128(res_lo_unsigned);
          _mm_store_si128((__m128i *)(&dst[i * dst_stride + j]), res_lo_0);

          const __m128i res_lo_1 = _mm256_extracti128_si256(res_lo_unsigned, 1);
          _mm_store_si128((__m128i *)(&dst[i * dst_stride + j + dst_stride]),
                          res_lo_1);

          const __m128i res_hi_0 = _mm256_castsi256_si128(res_hi_unsigned);
          _mm_store_si128((__m128i *)(&dst[i * dst_stride + j + 8]), res_hi_0);

          const __m128i res_hi_1 = _mm256_extracti128_si256(res_hi_unsigned, 1);
          _mm_store_si128(
              (__m128i *)(&dst[i * dst_stride + j + 8 + dst_stride]), res_hi_1);
        }
      }
      s[0] = s[1];
      s[1] = s[2];
      s[2] = s[3];

      s[4] = s[5];
      s[5] = s[6];
      s[6] = s[7];
    }
  }
}

void av1_dist_wtd_convolve_2d_avx2(const uint8_t *src, int src_stride,
                                   uint8_t *dst0, int dst_stride0, int w, int h,
                                   const InterpFilterParams *filter_params_x,
                                   const InterpFilterParams *filter_params_y,
                                   const int subpel_x_q4, const int subpel_y_q4,
                                   ConvolveParams *conv_params) {
  CONV_BUF_TYPE *dst = conv_params->dst;
  int dst_stride = conv_params->dst_stride;
  const int bd = 8;

  DECLARE_ALIGNED(32, int16_t, im_block[(MAX_SB_SIZE + MAX_FILTER_TAP) * 8]);
  int im_h = h + filter_params_y->taps - 1;
  int im_stride = 8;
  int i, j;
  const int fo_vert = filter_params_y->taps / 2 - 1;
  const int fo_horiz = filter_params_x->taps / 2 - 1;
  const uint8_t *const src_ptr = src - fo_vert * src_stride - fo_horiz;
  const __m256i wt = unpack_weights_avx2(conv_params);
  const int do_average = conv_params->do_average;
  const int use_dist_wtd_comp_avg = conv_params->use_dist_wtd_comp_avg;
  const int offset_0 =
      bd + 2 * FILTER_BITS - conv_params->round_0 - conv_params->round_1;
  const int offset = (1 << offset_0) + (1 << (offset_0 - 1));
  const __m256i offset_const = _mm256_set1_epi16(offset);
  const int rounding_shift =
      2 * FILTER_BITS - conv_params->round_0 - conv_params->round_1;
  const __m256i rounding_const = _mm256_set1_epi16((1 << rounding_shift) >> 1);
  __m256i filt[4], s[8], coeffs_x[4], coeffs_y[4];

  assert(conv_params->round_0 > 0);

  filt[0] = _mm256_load_si256((__m256i const *)filt_global_avx2);
  filt[1] = _mm256_load_si256((__m256i const *)(filt_global_avx2 + 32));
  filt[2] = _mm256_load_si256((__m256i const *)(filt_global_avx2 + 32 * 2));
  filt[3] = _mm256_load_si256((__m256i const *)(filt_global_avx2 + 32 * 3));

  prepare_coeffs_lowbd(filter_params_x, subpel_x_q4, coeffs_x);
  prepare_coeffs(filter_params_y, subpel_y_q4, coeffs_y);

  const __m256i round_const_h = _mm256_set1_epi16(
      ((1 << (conv_params->round_0 - 1)) >> 1) + (1 << (bd + FILTER_BITS - 2)));
  const __m128i round_shift_h = _mm_cvtsi32_si128(conv_params->round_0 - 1);

  const __m256i round_const_v = _mm256_set1_epi32(
      ((1 << conv_params->round_1) >> 1) -
      (1 << (bd + 2 * FILTER_BITS - conv_params->round_0 - 1)));
  const __m128i round_shift_v = _mm_cvtsi32_si128(conv_params->round_1);

  for (j = 0; j < w; j += 8) {
    /* Horizontal filter */
    {
      const uint8_t *src_h = src_ptr + j;
      for (i = 0; i < im_h; i += 2) {
        __m256i data =
            _mm256_castsi128_si256(_mm_loadu_si128((__m128i *)src_h));
        if (i + 1 < im_h)
          data = _mm256_inserti128_si256(
              data, _mm_loadu_si128((__m128i *)(src_h + src_stride)), 1);
        src_h += (src_stride << 1);
        __m256i res = convolve_lowbd_x(data, coeffs_x, filt);

        res = _mm256_sra_epi16(_mm256_add_epi16(res, round_const_h),
                               round_shift_h);

        _mm256_store_si256((__m256i *)&im_block[i * im_stride], res);
      }
    }

    /* Vertical filter */
    {
      __m256i s0 = _mm256_loadu_si256((__m256i *)(im_block + 0 * im_stride));
      __m256i s1 = _mm256_loadu_si256((__m256i *)(im_block + 1 * im_stride));
      __m256i s2 = _mm256_loadu_si256((__m256i *)(im_block + 2 * im_stride));
      __m256i s3 = _mm256_loadu_si256((__m256i *)(im_block + 3 * im_stride));
      __m256i s4 = _mm256_loadu_si256((__m256i *)(im_block + 4 * im_stride));
      __m256i s5 = _mm256_loadu_si256((__m256i *)(im_block + 5 * im_stride));

      s[0] = _mm256_unpacklo_epi16(s0, s1);
      s[1] = _mm256_unpacklo_epi16(s2, s3);
      s[2] = _mm256_unpacklo_epi16(s4, s5);

      s[4] = _mm256_unpackhi_epi16(s0, s1);
      s[5] = _mm256_unpackhi_epi16(s2, s3);
      s[6] = _mm256_unpackhi_epi16(s4, s5);

      for (i = 0; i < h; i += 2) {
        const int16_t *data = &im_block[i * im_stride];

        const __m256i s6 =
            _mm256_loadu_si256((__m256i *)(data + 6 * im_stride));
        const __m256i s7 =
            _mm256_loadu_si256((__m256i *)(data + 7 * im_stride));

        s[3] = _mm256_unpacklo_epi16(s6, s7);
        s[7] = _mm256_unpackhi_epi16(s6, s7);

        const __m256i res_a = convolve(s, coeffs_y);
        const __m256i res_a_round = _mm256_sra_epi32(
            _mm256_add_epi32(res_a, round_const_v), round_shift_v);

        if (w - j > 4) {
          const __m256i res_b = convolve(s + 4, coeffs_y);
          const __m256i res_b_round = _mm256_sra_epi32(
              _mm256_add_epi32(res_b, round_const_v), round_shift_v);
          const __m256i res_16b = _mm256_packs_epi32(res_a_round, res_b_round);
          const __m256i res_unsigned = _mm256_add_epi16(res_16b, offset_const);

          if (do_average) {
            const __m256i data_ref_0 =
                load_line2_avx2(&dst[i * dst_stride + j],
                                &dst[i * dst_stride + j + dst_stride]);
            const __m256i comp_avg_res = comp_avg(&data_ref_0, &res_unsigned,
                                                  &wt, use_dist_wtd_comp_avg);

            const __m256i round_result = convolve_rounding(
                &comp_avg_res, &offset_const, &rounding_const, rounding_shift);

            const __m256i res_8 =
                _mm256_packus_epi16(round_result, round_result);
            const __m128i res_0 = _mm256_castsi256_si128(res_8);
            const __m128i res_1 = _mm256_extracti128_si256(res_8, 1);

            _mm_storel_epi64((__m128i *)(&dst0[i * dst_stride0 + j]), res_0);
            _mm_storel_epi64(
                (__m128i *)((&dst0[i * dst_stride0 + j + dst_stride0])), res_1);
          } else {
            const __m128i res_0 = _mm256_castsi256_si128(res_unsigned);
            _mm_store_si128((__m128i *)(&dst[i * dst_stride + j]), res_0);

            const __m128i res_1 = _mm256_extracti128_si256(res_unsigned, 1);
            _mm_store_si128((__m128i *)(&dst[i * dst_stride + j + dst_stride]),
                            res_1);
          }
        } else {
          const __m256i res_16b = _mm256_packs_epi32(res_a_round, res_a_round);
          const __m256i res_unsigned = _mm256_add_epi16(res_16b, offset_const);

          if (do_average) {
            const __m256i data_ref_0 =
                load_line2_avx2(&dst[i * dst_stride + j],
                                &dst[i * dst_stride + j + dst_stride]);

            const __m256i comp_avg_res = comp_avg(&data_ref_0, &res_unsigned,
                                                  &wt, use_dist_wtd_comp_avg);

            const __m256i round_result = convolve_rounding(
                &comp_avg_res, &offset_const, &rounding_const, rounding_shift);

            const __m256i res_8 =
                _mm256_packus_epi16(round_result, round_result);
            const __m128i res_0 = _mm256_castsi256_si128(res_8);
            const __m128i res_1 = _mm256_extracti128_si256(res_8, 1);

            *(uint32_t *)(&dst0[i * dst_stride0 + j]) =
                _mm_cvtsi128_si32(res_0);
            *(uint32_t *)(&dst0[i * dst_stride0 + j + dst_stride0]) =
                _mm_cvtsi128_si32(res_1);

          } else {
            const __m128i res_0 = _mm256_castsi256_si128(res_unsigned);
            _mm_store_si128((__m128i *)(&dst[i * dst_stride + j]), res_0);

            const __m128i res_1 = _mm256_extracti128_si256(res_unsigned, 1);
            _mm_store_si128((__m128i *)(&dst[i * dst_stride + j + dst_stride]),
                            res_1);
          }
        }

        s[0] = s[1];
        s[1] = s[2];
        s[2] = s[3];

        s[4] = s[5];
        s[5] = s[6];
        s[6] = s[7];
      }
    }
  }
}

void av1_dist_wtd_convolve_2d_copy_avx2(
    const uint8_t *src, int src_stride, uint8_t *dst0, int dst_stride0, int w,
    int h, const InterpFilterParams *filter_params_x,
    const InterpFilterParams *filter_params_y, const int subpel_x_q4,
    const int subpel_y_q4, ConvolveParams *conv_params) {
  const int bd = 8;
  CONV_BUF_TYPE *dst = conv_params->dst;
  int dst_stride = conv_params->dst_stride;
  (void)filter_params_x;
  (void)filter_params_y;
  (void)subpel_x_q4;
  (void)subpel_y_q4;

  const int bits =
      FILTER_BITS * 2 - conv_params->round_1 - conv_params->round_0;
  const __m128i left_shift = _mm_cvtsi32_si128(bits);
  const int do_average = conv_params->do_average;
  const int use_dist_wtd_comp_avg = conv_params->use_dist_wtd_comp_avg;
  const __m256i wt = unpack_weights_avx2(conv_params);
  const __m256i zero = _mm256_setzero_si256();

  const int offset_0 =
      bd + 2 * FILTER_BITS - conv_params->round_0 - conv_params->round_1;
  const int offset = (1 << offset_0) + (1 << (offset_0 - 1));
  const __m256i offset_const = _mm256_set1_epi16(offset);
  const int rounding_shift =
      2 * FILTER_BITS - conv_params->round_0 - conv_params->round_1;
  const __m256i rounding_const = _mm256_set1_epi16((1 << rounding_shift) >> 1);
  int i, j;

  if (!(w % 16)) {
    for (i = 0; i < h; i += 1) {
      for (j = 0; j < w; j += 16) {
        const __m256i src_16bit = _mm256_cvtepu8_epi16(
            _mm_loadu_si128((__m128i *)(&src[i * src_stride + j])));

        const __m256i res = _mm256_sll_epi16(src_16bit, left_shift);
        const __m256i res_unsigned = _mm256_add_epi16(res, offset_const);

        if (do_average) {
          const __m256i data_ref_0 =
              _mm256_loadu_si256((__m256i *)(&dst[i * dst_stride + j]));

          const __m256i comp_avg_res =
              comp_avg(&data_ref_0, &res_unsigned, &wt, use_dist_wtd_comp_avg);

          const __m256i round_result = convolve_rounding(
              &comp_avg_res, &offset_const, &rounding_const, rounding_shift);

          const __m256i res_8 = _mm256_packus_epi16(round_result, round_result);
          const __m256i res_0 = _mm256_permute4x64_epi64(res_8, 0xD8);

          _mm_store_si128((__m128i *)(&dst0[i * dst_stride0 + j]),
                          _mm256_castsi256_si128(res_0));
        } else {
          _mm256_store_si256((__m256i *)(&dst[i * dst_stride + j]),
                             res_unsigned);
        }
      }
    }
  } else if (!(w % 4)) {
    for (i = 0; i < h; i += 2) {
      for (j = 0; j < w; j += 8) {
        const __m128i src_row_0 =
            _mm_loadl_epi64((__m128i *)(&src[i * src_stride + j]));
        const __m128i src_row_1 =
            _mm_loadl_epi64((__m128i *)(&src[i * src_stride + j + src_stride]));
        // since not all compilers yet support _mm256_set_m128i()
        const __m256i src_10 = _mm256_insertf128_si256(
            _mm256_castsi128_si256(src_row_0), src_row_1, 1);

        const __m256i src_16bit = _mm256_unpacklo_epi8(src_10, zero);

        const __m256i res = _mm256_sll_epi16(src_16bit, left_shift);

        const __m256i res_unsigned = _mm256_add_epi16(res, offset_const);

        // Accumulate values into the destination buffer
        if (do_average) {
          const __m256i data_ref_0 = load_line2_avx2(
              &dst[i * dst_stride + j], &dst[i * dst_stride + j + dst_stride]);
          const __m256i comp_avg_res =
              comp_avg(&data_ref_0, &res_unsigned, &wt, use_dist_wtd_comp_avg);

          const __m256i round_result = convolve_rounding(
              &comp_avg_res, &offset_const, &rounding_const, rounding_shift);

          const __m256i res_8 = _mm256_packus_epi16(round_result, round_result);
          const __m128i res_0 = _mm256_castsi256_si128(res_8);
          const __m128i res_1 = _mm256_extracti128_si256(res_8, 1);

          if (w > 4) {
            _mm_storel_epi64((__m128i *)(&dst0[i * dst_stride0 + j]), res_0);
            _mm_storel_epi64(
                (__m128i *)((&dst0[i * dst_stride0 + j + dst_stride0])), res_1);
          } else {
            *(uint32_t *)(&dst0[i * dst_stride0 + j]) =
                _mm_cvtsi128_si32(res_0);
            *(uint32_t *)(&dst0[i * dst_stride0 + j + dst_stride0]) =
                _mm_cvtsi128_si32(res_1);
          }
        } else {
          const __m128i res_0 = _mm256_castsi256_si128(res_unsigned);
          _mm_store_si128((__m128i *)(&dst[i * dst_stride + j]), res_0);

          const __m128i res_1 = _mm256_extracti128_si256(res_unsigned, 1);
          _mm_store_si128((__m128i *)(&dst[i * dst_stride + j + dst_stride]),
                          res_1);
        }
      }
    }
  }
}