/*
 * Copyright (c) 2017, 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/av1_rtcd.h"

#include "aom_dsp/aom_dsp_common.h"
#include "aom_dsp/x86/convolve_common_intrin.h"
#include "aom_dsp/x86/convolve_avx2.h"
#include "aom_dsp/x86/synonyms.h"

void av1_convolve_y_sr_avx2(const uint8_t *src, int src_stride, uint8_t *dst,
                            int dst_stride, int w, int h,
                            const InterpFilterParams *filter_params_y,
                            const int subpel_y_qn) {
  if (filter_params_y->taps > 8) {
    if (w < 4 || h < 4) {
      av1_convolve_y_sr_c(src, src_stride, dst, dst_stride, w, h,
                          filter_params_y, subpel_y_qn);
    } else {
      av1_convolve_y_sr_12tap_sse2(src, src_stride, dst, dst_stride, w, h,
                                   filter_params_y, subpel_y_qn);
    }
  } else {
    int i, j, vert_tap = SUBPEL_TAPS;
    // right shift is F-1 because we are already dividing
    // filter co-efficients by 2
    const int right_shift_bits = (FILTER_BITS - 1);
    const __m128i right_shift = _mm_cvtsi32_si128(right_shift_bits);
    const __m256i right_shift_const =
        _mm256_set1_epi16((1 << right_shift_bits) >> 1);

    __m256i coeffs[4], s[8];
    __m128i d[6];

    // Condition for checking valid vert_filt taps
    const int16_t *const filter = av1_get_interp_filter_subpel_kernel(
        filter_params_y, subpel_y_qn & SUBPEL_MASK);
    if (!(filter[0] | filter[1] | filter[6] | filter[7])) {
      vert_tap = 4;
    } else if (!(filter[0] | filter[7])) {
      vert_tap = 6;
    }

    if (vert_tap == 6)
      prepare_coeffs_6t_lowbd(filter_params_y, subpel_y_qn, coeffs);
    else
      prepare_coeffs_lowbd(filter_params_y, subpel_y_qn, coeffs);

    // vert_filt as 4 tap
    if (vert_tap == 4) {
      const int fo_vert = 1;
      const uint8_t *const src_ptr = src - fo_vert * src_stride;
      for (j = 0; j < w; j += 16) {
        const uint8_t *data = &src_ptr[j];
        d[0] = _mm_loadu_si128((__m128i *)(data + 0 * src_stride));
        d[1] = _mm_loadu_si128((__m128i *)(data + 1 * src_stride));
        d[2] = _mm_loadu_si128((__m128i *)(data + 2 * src_stride));
        d[3] = _mm_loadu_si128((__m128i *)(data + 3 * src_stride));
        d[4] = _mm_loadu_si128((__m128i *)(data + 4 * src_stride));

        // Load lines a and b. Line a to lower 128, line b to upper 128
        const __m256i src_01a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[0]), _mm256_castsi128_si256(d[1]), 0x20);

        const __m256i src_12a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[1]), _mm256_castsi128_si256(d[2]), 0x20);

        const __m256i src_23a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[2]), _mm256_castsi128_si256(d[3]), 0x20);

        const __m256i src_34a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[3]), _mm256_castsi128_si256(d[4]), 0x20);

        s[0] = _mm256_unpacklo_epi8(src_01a, src_12a);
        s[1] = _mm256_unpacklo_epi8(src_23a, src_34a);

        s[3] = _mm256_unpackhi_epi8(src_01a, src_12a);
        s[4] = _mm256_unpackhi_epi8(src_23a, src_34a);

        for (i = 0; i < h; i += 2) {
          data = &src_ptr[i * src_stride + j];
          d[5] = _mm_loadu_si128((__m128i *)(data + 5 * src_stride));
          const __m256i src_45a = _mm256_permute2x128_si256(
              _mm256_castsi128_si256(d[4]), _mm256_castsi128_si256(d[5]), 0x20);

          d[4] = _mm_loadu_si128((__m128i *)(data + 6 * src_stride));
          const __m256i src_56a = _mm256_permute2x128_si256(
              _mm256_castsi128_si256(d[5]), _mm256_castsi128_si256(d[4]), 0x20);

          s[2] = _mm256_unpacklo_epi8(src_45a, src_56a);
          s[5] = _mm256_unpackhi_epi8(src_45a, src_56a);

          const __m256i res_lo = convolve_lowbd_4tap(s, coeffs + 1);
          /* rounding code */
          // shift by F - 1
          const __m256i res_16b_lo = _mm256_sra_epi16(
              _mm256_add_epi16(res_lo, right_shift_const), right_shift);
          // 8 bit conversion and saturation to uint8
          __m256i res_8b_lo = _mm256_packus_epi16(res_16b_lo, res_16b_lo);

          if (w - j > 8) {
            const __m256i res_hi = convolve_lowbd_4tap(s + 3, coeffs + 1);

            /* rounding code */
            // shift by F - 1
            const __m256i res_16b_hi = _mm256_sra_epi16(
                _mm256_add_epi16(res_hi, right_shift_const), right_shift);
            // 8 bit conversion and saturation to uint8
            __m256i res_8b_hi = _mm256_packus_epi16(res_16b_hi, res_16b_hi);

            __m256i res_a = _mm256_unpacklo_epi64(res_8b_lo, res_8b_hi);

            const __m128i res_0 = _mm256_castsi256_si128(res_a);
            const __m128i res_1 = _mm256_extracti128_si256(res_a, 1);

            _mm_storeu_si128((__m128i *)&dst[i * dst_stride + j], res_0);
            _mm_storeu_si128((__m128i *)&dst[i * dst_stride + j + dst_stride],
                             res_1);
          } else {
            const __m128i res_0 = _mm256_castsi256_si128(res_8b_lo);
            const __m128i res_1 = _mm256_extracti128_si256(res_8b_lo, 1);
            if (w - j > 4) {
              _mm_storel_epi64((__m128i *)&dst[i * dst_stride + j], res_0);
              _mm_storel_epi64((__m128i *)&dst[i * dst_stride + j + dst_stride],
                               res_1);
            } else if (w - j > 2) {
              xx_storel_32(&dst[i * dst_stride + j], res_0);
              xx_storel_32(&dst[i * dst_stride + j + dst_stride], res_1);
            } else {
              __m128i *const p_0 = (__m128i *)&dst[i * dst_stride + j];
              __m128i *const p_1 =
                  (__m128i *)&dst[i * dst_stride + j + dst_stride];
              *(uint16_t *)p_0 = (uint16_t)_mm_cvtsi128_si32(res_0);
              *(uint16_t *)p_1 = (uint16_t)_mm_cvtsi128_si32(res_1);
            }
          }
          s[0] = s[1];
          s[1] = s[2];

          s[3] = s[4];
          s[4] = s[5];
        }
      }
    } else if (vert_tap == 6) {
      const int fo_vert = vert_tap / 2 - 1;
      const uint8_t *const src_ptr = src - fo_vert * src_stride;

      for (j = 0; j < w; j += 16) {
        const uint8_t *data = &src_ptr[j];
        __m256i src6;

        d[0] = _mm_loadu_si128((__m128i *)(data + 0 * src_stride));
        d[1] = _mm_loadu_si128((__m128i *)(data + 1 * src_stride));
        d[2] = _mm_loadu_si128((__m128i *)(data + 2 * src_stride));
        d[3] = _mm_loadu_si128((__m128i *)(data + 3 * src_stride));
        // Load lines a and b. Line a to lower 128, line b to upper 128
        const __m256i src_01a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[0]), _mm256_castsi128_si256(d[1]), 0x20);

        const __m256i src_12a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[1]), _mm256_castsi128_si256(d[2]), 0x20);

        const __m256i src_23a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[2]), _mm256_castsi128_si256(d[3]), 0x20);

        src6 = _mm256_castsi128_si256(
            _mm_loadu_si128((__m128i *)(data + 4 * src_stride)));
        const __m256i src_34a =
            _mm256_permute2x128_si256(_mm256_castsi128_si256(d[3]), src6, 0x20);

        s[0] = _mm256_unpacklo_epi8(src_01a, src_12a);
        s[1] = _mm256_unpacklo_epi8(src_23a, src_34a);

        s[3] = _mm256_unpackhi_epi8(src_01a, src_12a);
        s[4] = _mm256_unpackhi_epi8(src_23a, src_34a);

        for (i = 0; i < h; i += 2) {
          data = &src_ptr[i * src_stride + j];
          const __m256i src_45a = _mm256_permute2x128_si256(
              src6,
              _mm256_castsi128_si256(
                  _mm_loadu_si128((__m128i *)(data + 5 * src_stride))),
              0x20);

          src6 = _mm256_castsi128_si256(
              _mm_loadu_si128((__m128i *)(data + 6 * src_stride)));
          const __m256i src_56a = _mm256_permute2x128_si256(
              _mm256_castsi128_si256(
                  _mm_loadu_si128((__m128i *)(data + 5 * src_stride))),
              src6, 0x20);

          s[2] = _mm256_unpacklo_epi8(src_45a, src_56a);
          s[5] = _mm256_unpackhi_epi8(src_45a, src_56a);

          const __m256i res_lo = convolve_lowbd_6tap(s, coeffs);

          /* rounding code */
          // shift by F - 1
          const __m256i res_16b_lo = _mm256_sra_epi16(
              _mm256_add_epi16(res_lo, right_shift_const), right_shift);
          // 8 bit conversion and saturation to uint8
          __m256i res_8b_lo = _mm256_packus_epi16(res_16b_lo, res_16b_lo);

          if (w - j > 8) {
            const __m256i res_hi = convolve_lowbd_6tap(s + 3, coeffs);

            /* rounding code */
            // shift by F - 1
            const __m256i res_16b_hi = _mm256_sra_epi16(
                _mm256_add_epi16(res_hi, right_shift_const), right_shift);
            // 8 bit conversion and saturation to uint8
            __m256i res_8b_hi = _mm256_packus_epi16(res_16b_hi, res_16b_hi);

            __m256i res_a = _mm256_unpacklo_epi64(res_8b_lo, res_8b_hi);

            const __m128i res_0 = _mm256_castsi256_si128(res_a);
            const __m128i res_1 = _mm256_extracti128_si256(res_a, 1);

            _mm_storeu_si128((__m128i *)&dst[i * dst_stride + j], res_0);
            _mm_storeu_si128((__m128i *)&dst[i * dst_stride + j + dst_stride],
                             res_1);
          } else {
            const __m128i res_0 = _mm256_castsi256_si128(res_8b_lo);
            const __m128i res_1 = _mm256_extracti128_si256(res_8b_lo, 1);
            if (w - j > 4) {
              _mm_storel_epi64((__m128i *)&dst[i * dst_stride + j], res_0);
              _mm_storel_epi64((__m128i *)&dst[i * dst_stride + j + dst_stride],
                               res_1);
            } else if (w - j > 2) {
              xx_storel_32(&dst[i * dst_stride + j], res_0);
              xx_storel_32(&dst[i * dst_stride + j + dst_stride], res_1);
            } else {
              __m128i *const p_0 = (__m128i *)&dst[i * dst_stride + j];
              __m128i *const p_1 =
                  (__m128i *)&dst[i * dst_stride + j + dst_stride];
              *(uint16_t *)p_0 = (uint16_t)_mm_cvtsi128_si32(res_0);
              *(uint16_t *)p_1 = (uint16_t)_mm_cvtsi128_si32(res_1);
            }
          }
          s[0] = s[1];
          s[1] = s[2];
          s[3] = s[4];
          s[4] = s[5];
        }
      }
    } else {
      const int fo_vert = filter_params_y->taps / 2 - 1;
      const uint8_t *const src_ptr = src - fo_vert * src_stride;

      for (j = 0; j < w; j += 16) {
        const uint8_t *data = &src_ptr[j];
        __m256i src6;

        d[0] = _mm_loadu_si128((__m128i *)(data + 0 * src_stride));
        d[1] = _mm_loadu_si128((__m128i *)(data + 1 * src_stride));
        d[2] = _mm_loadu_si128((__m128i *)(data + 2 * src_stride));
        d[3] = _mm_loadu_si128((__m128i *)(data + 3 * src_stride));
        d[4] = _mm_loadu_si128((__m128i *)(data + 4 * src_stride));
        d[5] = _mm_loadu_si128((__m128i *)(data + 5 * src_stride));
        // Load lines a and b. Line a to lower 128, line b to upper 128
        const __m256i src_01a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[0]), _mm256_castsi128_si256(d[1]), 0x20);

        const __m256i src_12a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[1]), _mm256_castsi128_si256(d[2]), 0x20);

        const __m256i src_23a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[2]), _mm256_castsi128_si256(d[3]), 0x20);

        const __m256i src_34a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[3]), _mm256_castsi128_si256(d[4]), 0x20);

        const __m256i src_45a = _mm256_permute2x128_si256(
            _mm256_castsi128_si256(d[4]), _mm256_castsi128_si256(d[5]), 0x20);

        src6 = _mm256_castsi128_si256(
            _mm_loadu_si128((__m128i *)(data + 6 * src_stride)));
        const __m256i src_56a =
            _mm256_permute2x128_si256(_mm256_castsi128_si256(d[5]), src6, 0x20);

        s[0] = _mm256_unpacklo_epi8(src_01a, src_12a);
        s[1] = _mm256_unpacklo_epi8(src_23a, src_34a);
        s[2] = _mm256_unpacklo_epi8(src_45a, src_56a);

        s[4] = _mm256_unpackhi_epi8(src_01a, src_12a);
        s[5] = _mm256_unpackhi_epi8(src_23a, src_34a);
        s[6] = _mm256_unpackhi_epi8(src_45a, src_56a);

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

          src6 = _mm256_castsi128_si256(
              _mm_loadu_si128((__m128i *)(data + 8 * src_stride)));
          const __m256i src_78a = _mm256_permute2x128_si256(
              _mm256_castsi128_si256(
                  _mm_loadu_si128((__m128i *)(data + 7 * src_stride))),
              src6, 0x20);

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

          const __m256i res_lo = convolve_lowbd(s, coeffs);

          /* rounding code */
          // shift by F - 1
          const __m256i res_16b_lo = _mm256_sra_epi16(
              _mm256_add_epi16(res_lo, right_shift_const), right_shift);
          // 8 bit conversion and saturation to uint8
          __m256i res_8b_lo = _mm256_packus_epi16(res_16b_lo, res_16b_lo);

          if (w - j > 8) {
            const __m256i res_hi = convolve_lowbd(s + 4, coeffs);

            /* rounding code */
            // shift by F - 1
            const __m256i res_16b_hi = _mm256_sra_epi16(
                _mm256_add_epi16(res_hi, right_shift_const), right_shift);
            // 8 bit conversion and saturation to uint8
            __m256i res_8b_hi = _mm256_packus_epi16(res_16b_hi, res_16b_hi);

            __m256i res_a = _mm256_unpacklo_epi64(res_8b_lo, res_8b_hi);

            const __m128i res_0 = _mm256_castsi256_si128(res_a);
            const __m128i res_1 = _mm256_extracti128_si256(res_a, 1);

            _mm_storeu_si128((__m128i *)&dst[i * dst_stride + j], res_0);
            _mm_storeu_si128((__m128i *)&dst[i * dst_stride + j + dst_stride],
                             res_1);
          } else {
            const __m128i res_0 = _mm256_castsi256_si128(res_8b_lo);
            const __m128i res_1 = _mm256_extracti128_si256(res_8b_lo, 1);
            if (w - j > 4) {
              _mm_storel_epi64((__m128i *)&dst[i * dst_stride + j], res_0);
              _mm_storel_epi64((__m128i *)&dst[i * dst_stride + j + dst_stride],
                               res_1);
            } else if (w - j > 2) {
              xx_storel_32(&dst[i * dst_stride + j], res_0);
              xx_storel_32(&dst[i * dst_stride + j + dst_stride], res_1);
            } else {
              __m128i *const p_0 = (__m128i *)&dst[i * dst_stride + j];
              __m128i *const p_1 =
                  (__m128i *)&dst[i * dst_stride + j + dst_stride];
              *(uint16_t *)p_0 = (uint16_t)_mm_cvtsi128_si32(res_0);
              *(uint16_t *)p_1 = (uint16_t)_mm_cvtsi128_si32(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_convolve_x_sr_avx2(const uint8_t *src, int src_stride, uint8_t *dst,
                            int dst_stride, int w, int h,
                            const InterpFilterParams *filter_params_x,
                            const int subpel_x_qn,
                            ConvolveParams *conv_params) {
  if (filter_params_x->taps > 8) {
    if (w < 4) {
      av1_convolve_x_sr_c(src, src_stride, dst, dst_stride, w, h,
                          filter_params_x, subpel_x_qn, conv_params);
    } else {
      av1_convolve_x_sr_12tap_sse2(src, src_stride, dst, dst_stride, w, h,
                                   filter_params_x, subpel_x_qn, conv_params);
    }
  } else {
    const int bits = FILTER_BITS - conv_params->round_0;

    const __m256i round_0_const =
        _mm256_set1_epi16((1 << (conv_params->round_0 - 1)) >> 1);
    const __m128i round_0_shift = _mm_cvtsi32_si128(conv_params->round_0 - 1);
    const __m256i round_const = _mm256_set1_epi16((1 << bits) >> 1);
    const __m128i round_shift = _mm_cvtsi32_si128(bits);
    int i, horiz_tap = SUBPEL_TAPS;

    assert(bits >= 0);
    assert((FILTER_BITS - conv_params->round_1) >= 0 ||
           ((conv_params->round_0 + conv_params->round_1) == 2 * FILTER_BITS));
    assert(conv_params->round_0 > 0);

    __m256i coeffs[4], filt[4];
    filt[0] = _mm256_load_si256((__m256i const *)(filt_global_avx2));
    filt[1] = _mm256_load_si256((__m256i const *)(filt_global_avx2 + 32));

    const int16_t *const filter = av1_get_interp_filter_subpel_kernel(
        filter_params_x, subpel_x_qn & SUBPEL_MASK);
    if (!(filter[0] | filter[1] | filter[6] | filter[7])) {
      horiz_tap = 4;
    } else if (!(filter[0] | filter[7])) {
      horiz_tap = 6;
    }

    if (horiz_tap == 6)
      prepare_coeffs_6t_lowbd(filter_params_x, subpel_x_qn, coeffs);
    else
      prepare_coeffs_lowbd(filter_params_x, subpel_x_qn, coeffs);

    // horz_filt as 4 tap
    if (horiz_tap == 4) {
      const int fo_horiz = 1;
      const uint8_t *const src_ptr = src - fo_horiz;
      if (w <= 8) {
        for (i = 0; i < h; i += 2) {
          const __m256i data = _mm256_permute2x128_si256(
              _mm256_castsi128_si256(
                  _mm_loadu_si128((__m128i *)(&src_ptr[i * src_stride]))),
              _mm256_castsi128_si256(_mm_loadu_si128(
                  (__m128i *)(&src_ptr[i * src_stride + src_stride]))),
              0x20);

          __m256i res_16b = convolve_lowbd_x_4tap(data, coeffs + 1, filt);

          res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_0_const),
                                     round_0_shift);

          res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_const),
                                     round_shift);

          /* rounding code */
          // 8 bit conversion and saturation to uint8
          __m256i res_8b = _mm256_packus_epi16(res_16b, res_16b);

          const __m128i res_0 = _mm256_castsi256_si128(res_8b);
          const __m128i res_1 = _mm256_extracti128_si256(res_8b, 1);

          if (w > 4) {
            _mm_storel_epi64((__m128i *)&dst[i * dst_stride], res_0);
            _mm_storel_epi64((__m128i *)&dst[i * dst_stride + dst_stride],
                             res_1);
          } else if (w > 2) {
            xx_storel_32(&dst[i * dst_stride], res_0);
            xx_storel_32(&dst[i * dst_stride + dst_stride], res_1);
          } else {
            __m128i *const p_0 = (__m128i *)&dst[i * dst_stride];
            __m128i *const p_1 = (__m128i *)&dst[i * dst_stride + dst_stride];
            *(uint16_t *)p_0 = (uint16_t)_mm_cvtsi128_si32(res_0);
            *(uint16_t *)p_1 = (uint16_t)_mm_cvtsi128_si32(res_1);
          }
        }
      } else {
        for (i = 0; i < h; ++i) {
          for (int j = 0; j < w; j += 16) {
            // 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 8 9 10 11 12 13 14 15 16 17
            // 18 19 20 21 22 23
            const __m256i data = _mm256_inserti128_si256(
                _mm256_loadu_si256((__m256i *)&src_ptr[(i * src_stride) + j]),
                _mm_loadu_si128(
                    (__m128i *)&src_ptr[(i * src_stride) + (j + 8)]),
                1);

            __m256i res_16b = convolve_lowbd_x_4tap(data, coeffs + 1, filt);

            res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_0_const),
                                       round_0_shift);

            res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_const),
                                       round_shift);

            /* rounding code */
            // 8 bit conversion and saturation to uint8
            __m256i res_8b = _mm256_packus_epi16(res_16b, res_16b);

            // Store values into the destination buffer
            // 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
            res_8b = _mm256_permute4x64_epi64(res_8b, 216);
            __m128i res = _mm256_castsi256_si128(res_8b);
            _mm_storeu_si128((__m128i *)&dst[i * dst_stride + j], res);
          }
        }
      }
    } else if (horiz_tap == 6) {
      const int fo_horiz = horiz_tap / 2 - 1;
      const uint8_t *const src_ptr = src - fo_horiz;
      filt[2] = _mm256_load_si256((__m256i const *)(filt_global_avx2 + 32 * 2));
      filt[3] = _mm256_load_si256((__m256i const *)(filt_global_avx2 + 32 * 3));

      if (w <= 8) {
        for (i = 0; i < h; i += 2) {
          const __m256i data = _mm256_permute2x128_si256(
              _mm256_castsi128_si256(
                  _mm_loadu_si128((__m128i *)(&src_ptr[i * src_stride]))),
              _mm256_castsi128_si256(_mm_loadu_si128(
                  (__m128i *)(&src_ptr[i * src_stride + src_stride]))),
              0x20);

          __m256i res_16b = convolve_lowbd_x_6tap(data, coeffs, filt);

          res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_0_const),
                                     round_0_shift);

          res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_const),
                                     round_shift);

          /* rounding code */
          // 8 bit conversion and saturation to uint8
          __m256i res_8b = _mm256_packus_epi16(res_16b, res_16b);

          const __m128i res_0 = _mm256_castsi256_si128(res_8b);
          const __m128i res_1 = _mm256_extracti128_si256(res_8b, 1);
          if (w > 4) {
            _mm_storel_epi64((__m128i *)&dst[i * dst_stride], res_0);
            _mm_storel_epi64((__m128i *)&dst[i * dst_stride + dst_stride],
                             res_1);
          } else if (w > 2) {
            xx_storel_32(&dst[i * dst_stride], res_0);
            xx_storel_32(&dst[i * dst_stride + dst_stride], res_1);
          } else {
            __m128i *const p_0 = (__m128i *)&dst[i * dst_stride];
            __m128i *const p_1 = (__m128i *)&dst[i * dst_stride + dst_stride];
            *(uint16_t *)p_0 = _mm_cvtsi128_si32(res_0);
            *(uint16_t *)p_1 = _mm_cvtsi128_si32(res_1);
          }
        }
      } else {
        for (i = 0; i < h; ++i) {
          for (int j = 0; j < w; j += 16) {
            // 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 8 9 10 11 12 13 14 15 16 17
            // 18 19 20 21 22 23
            const __m256i data = _mm256_inserti128_si256(
                _mm256_loadu_si256((__m256i *)&src_ptr[(i * src_stride) + j]),
                _mm_loadu_si128(
                    (__m128i *)&src_ptr[(i * src_stride) + (j + 8)]),
                1);

            __m256i res_16b = convolve_lowbd_x_6tap(data, coeffs, filt);

            res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_0_const),
                                       round_0_shift);

            res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_const),
                                       round_shift);

            /* rounding code */
            // 8 bit conversion and saturation to uint8
            __m256i res_8b = _mm256_packus_epi16(res_16b, res_16b);

            // Store values into the destination buffer
            // 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
            res_8b = _mm256_permute4x64_epi64(res_8b, 216);
            __m128i res = _mm256_castsi256_si128(res_8b);
            _mm_storeu_si128((__m128i *)&dst[i * dst_stride + j], res);
          }
        }
      }
    } else {
      const int fo_horiz = filter_params_x->taps / 2 - 1;
      const uint8_t *const src_ptr = src - fo_horiz;
      filt[2] = _mm256_load_si256((__m256i const *)(filt_global_avx2 + 32 * 2));
      filt[3] = _mm256_load_si256((__m256i const *)(filt_global_avx2 + 32 * 3));

      if (w <= 8) {
        for (i = 0; i < h; i += 2) {
          const __m256i data = _mm256_permute2x128_si256(
              _mm256_castsi128_si256(
                  _mm_loadu_si128((__m128i *)(&src_ptr[i * src_stride]))),
              _mm256_castsi128_si256(_mm_loadu_si128(
                  (__m128i *)(&src_ptr[i * src_stride + src_stride]))),
              0x20);

          __m256i res_16b = convolve_lowbd_x(data, coeffs, filt);

          res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_0_const),
                                     round_0_shift);

          res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_const),
                                     round_shift);

          /* rounding code */
          // 8 bit conversion and saturation to uint8
          __m256i res_8b = _mm256_packus_epi16(res_16b, res_16b);

          const __m128i res_0 = _mm256_castsi256_si128(res_8b);
          const __m128i res_1 = _mm256_extracti128_si256(res_8b, 1);
          if (w > 4) {
            _mm_storel_epi64((__m128i *)&dst[i * dst_stride], res_0);
            _mm_storel_epi64((__m128i *)&dst[i * dst_stride + dst_stride],
                             res_1);
          } else if (w > 2) {
            xx_storel_32(&dst[i * dst_stride], res_0);
            xx_storel_32(&dst[i * dst_stride + dst_stride], res_1);
          } else {
            __m128i *const p_0 = (__m128i *)&dst[i * dst_stride];
            __m128i *const p_1 = (__m128i *)&dst[i * dst_stride + dst_stride];
            *(uint16_t *)p_0 = _mm_cvtsi128_si32(res_0);
            *(uint16_t *)p_1 = _mm_cvtsi128_si32(res_1);
          }
        }
      } else {
        for (i = 0; i < h; ++i) {
          for (int j = 0; j < w; j += 16) {
            // 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 8 9 10 11 12 13 14 15 16 17
            // 18 19 20 21 22 23
            const __m256i data = _mm256_inserti128_si256(
                _mm256_loadu_si256((__m256i *)&src_ptr[(i * src_stride) + j]),
                _mm_loadu_si128(
                    (__m128i *)&src_ptr[(i * src_stride) + (j + 8)]),
                1);

            __m256i res_16b = convolve_lowbd_x(data, coeffs, filt);

            res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_0_const),
                                       round_0_shift);

            res_16b = _mm256_sra_epi16(_mm256_add_epi16(res_16b, round_const),
                                       round_shift);

            /* rounding code */
            // 8 bit conversion and saturation to uint8
            __m256i res_8b = _mm256_packus_epi16(res_16b, res_16b);

            // Store values into the destination buffer
            // 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
            res_8b = _mm256_permute4x64_epi64(res_8b, 216);
            __m128i res = _mm256_castsi256_si128(res_8b);
            _mm_storeu_si128((__m128i *)&dst[i * dst_stride + j], res);
          }
        }
      }
    }
  }
}