/*
 * 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 <tmmintrin.h>

#include "config/aom_dsp_rtcd.h"

#include "aom_dsp/aom_filter.h"
#include "aom_dsp/x86/convolve_sse2.h"

void av1_dist_wtd_convolve_2d_ssse3(
    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_qn,
    const int subpel_y_qn, ConvolveParams *conv_params) {
  CONV_BUF_TYPE *dst = conv_params->dst;
  int dst_stride = conv_params->dst_stride;
  const int bd = 8;

  DECLARE_ALIGNED(16, int16_t,
                  im_block[(MAX_SB_SIZE + MAX_FILTER_TAP - 1) * MAX_SB_SIZE]);
  int im_h = h + filter_params_y->taps - 1;
  int im_stride = MAX_SB_SIZE;
  int i, j;
  const int fo_vert = filter_params_y->taps / 2 - 1;
  const int fo_horiz = filter_params_x->taps / 2 - 1;
  const int do_average = conv_params->do_average;
  const int use_wtd_comp_avg = is_uneven_wtd_comp_avg(conv_params);
  const int w0 = conv_params->fwd_offset;
  const int w1 = conv_params->bck_offset;
  const __m128i wt0 = _mm_set1_epi16(w0);
  const __m128i wt1 = _mm_set1_epi16(w1);
  const uint8_t *const src_ptr = src - fo_vert * src_stride - fo_horiz;

  const __m128i zero = _mm_setzero_si128();

  const __m128i wt = _mm_unpacklo_epi16(wt0, wt1);

  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 __m128i offset_const = _mm_set1_epi16(offset);
  const int rounding_shift =
      2 * FILTER_BITS - conv_params->round_0 - conv_params->round_1;
  const __m128i rounding_const = _mm_set1_epi16((1 << rounding_shift) >> 1);

  /* Horizontal filter */
  {
    const int16_t *x_filter = av1_get_interp_filter_subpel_kernel(
        filter_params_x, subpel_x_qn & SUBPEL_MASK);
    const __m128i coeffs_x = _mm_loadu_si128((__m128i *)x_filter);

    // coeffs 0 1 0 1 2 3 2 3
    const __m128i tmp_0 = _mm_unpacklo_epi32(coeffs_x, coeffs_x);
    // coeffs 4 5 4 5 6 7 6 7
    const __m128i tmp_1 = _mm_unpackhi_epi32(coeffs_x, coeffs_x);

    // coeffs 0 1 0 1 0 1 0 1
    const __m128i coeff_01 = _mm_unpacklo_epi64(tmp_0, tmp_0);
    // coeffs 2 3 2 3 2 3 2 3
    const __m128i coeff_23 = _mm_unpackhi_epi64(tmp_0, tmp_0);
    // coeffs 4 5 4 5 4 5 4 5
    const __m128i coeff_45 = _mm_unpacklo_epi64(tmp_1, tmp_1);
    // coeffs 6 7 6 7 6 7 6 7
    const __m128i coeff_67 = _mm_unpackhi_epi64(tmp_1, tmp_1);

    const __m128i round_const = _mm_set1_epi32(
        ((1 << conv_params->round_0) >> 1) + (1 << (bd + FILTER_BITS - 1)));
    const __m128i round_shift = _mm_cvtsi32_si128(conv_params->round_0);

    for (i = 0; i < im_h; ++i) {
      for (j = 0; j < w; j += 8) {
        const __m128i data =
            _mm_loadu_si128((__m128i *)&src_ptr[i * src_stride + j]);

        const __m128i src_lo = _mm_unpacklo_epi8(data, zero);
        const __m128i src_hi = _mm_unpackhi_epi8(data, zero);

        // Filter even-index pixels
        const __m128i res_0 = _mm_madd_epi16(src_lo, coeff_01);
        const __m128i src_2 = _mm_alignr_epi8(src_hi, src_lo, 4);
        const __m128i res_2 = _mm_madd_epi16(src_2, coeff_23);
        const __m128i src_4 = _mm_alignr_epi8(src_hi, src_lo, 8);
        const __m128i res_4 = _mm_madd_epi16(src_4, coeff_45);
        const __m128i src_6 = _mm_alignr_epi8(src_hi, src_lo, 12);
        const __m128i res_6 = _mm_madd_epi16(src_6, coeff_67);

        __m128i res_even = _mm_add_epi32(_mm_add_epi32(res_0, res_4),
                                         _mm_add_epi32(res_2, res_6));
        res_even =
            _mm_sra_epi32(_mm_add_epi32(res_even, round_const), round_shift);

        // Filter odd-index pixels
        const __m128i src_1 = _mm_alignr_epi8(src_hi, src_lo, 2);
        const __m128i res_1 = _mm_madd_epi16(src_1, coeff_01);
        const __m128i src_3 = _mm_alignr_epi8(src_hi, src_lo, 6);
        const __m128i res_3 = _mm_madd_epi16(src_3, coeff_23);
        const __m128i src_5 = _mm_alignr_epi8(src_hi, src_lo, 10);
        const __m128i res_5 = _mm_madd_epi16(src_5, coeff_45);
        const __m128i src_7 = _mm_alignr_epi8(src_hi, src_lo, 14);
        const __m128i res_7 = _mm_madd_epi16(src_7, coeff_67);

        __m128i res_odd = _mm_add_epi32(_mm_add_epi32(res_1, res_5),
                                        _mm_add_epi32(res_3, res_7));
        res_odd =
            _mm_sra_epi32(_mm_add_epi32(res_odd, round_const), round_shift);

        // Pack in the column order 0, 2, 4, 6, 1, 3, 5, 7
        __m128i res = _mm_packs_epi32(res_even, res_odd);
        _mm_store_si128((__m128i *)&im_block[i * im_stride + j], res);
      }
    }
  }

  /* Vertical filter */
  {
    const int16_t *y_filter = av1_get_interp_filter_subpel_kernel(
        filter_params_y, subpel_y_qn & SUBPEL_MASK);
    const __m128i coeffs_y = _mm_loadu_si128((__m128i *)y_filter);

    // coeffs 0 1 0 1 2 3 2 3
    const __m128i tmp_0 = _mm_unpacklo_epi32(coeffs_y, coeffs_y);
    // coeffs 4 5 4 5 6 7 6 7
    const __m128i tmp_1 = _mm_unpackhi_epi32(coeffs_y, coeffs_y);

    // coeffs 0 1 0 1 0 1 0 1
    const __m128i coeff_01 = _mm_unpacklo_epi64(tmp_0, tmp_0);
    // coeffs 2 3 2 3 2 3 2 3
    const __m128i coeff_23 = _mm_unpackhi_epi64(tmp_0, tmp_0);
    // coeffs 4 5 4 5 4 5 4 5
    const __m128i coeff_45 = _mm_unpacklo_epi64(tmp_1, tmp_1);
    // coeffs 6 7 6 7 6 7 6 7
    const __m128i coeff_67 = _mm_unpackhi_epi64(tmp_1, tmp_1);

    const __m128i round_const = _mm_set1_epi32(
        ((1 << conv_params->round_1) >> 1) -
        (1 << (bd + 2 * FILTER_BITS - conv_params->round_0 - 1)));
    const __m128i round_shift = _mm_cvtsi32_si128(conv_params->round_1);

    for (i = 0; i < h; ++i) {
      for (j = 0; j < w; j += 8) {
        // Filter even-index pixels
        const int16_t *data = &im_block[i * im_stride + j];
        const __m128i src_0 =
            _mm_unpacklo_epi16(*(__m128i *)(data + 0 * im_stride),
                               *(__m128i *)(data + 1 * im_stride));
        const __m128i src_2 =
            _mm_unpacklo_epi16(*(__m128i *)(data + 2 * im_stride),
                               *(__m128i *)(data + 3 * im_stride));
        const __m128i src_4 =
            _mm_unpacklo_epi16(*(__m128i *)(data + 4 * im_stride),
                               *(__m128i *)(data + 5 * im_stride));
        const __m128i src_6 =
            _mm_unpacklo_epi16(*(__m128i *)(data + 6 * im_stride),
                               *(__m128i *)(data + 7 * im_stride));

        const __m128i res_0 = _mm_madd_epi16(src_0, coeff_01);
        const __m128i res_2 = _mm_madd_epi16(src_2, coeff_23);
        const __m128i res_4 = _mm_madd_epi16(src_4, coeff_45);
        const __m128i res_6 = _mm_madd_epi16(src_6, coeff_67);

        const __m128i res_even = _mm_add_epi32(_mm_add_epi32(res_0, res_2),
                                               _mm_add_epi32(res_4, res_6));

        // Filter odd-index pixels
        const __m128i src_1 =
            _mm_unpackhi_epi16(*(__m128i *)(data + 0 * im_stride),
                               *(__m128i *)(data + 1 * im_stride));
        const __m128i src_3 =
            _mm_unpackhi_epi16(*(__m128i *)(data + 2 * im_stride),
                               *(__m128i *)(data + 3 * im_stride));
        const __m128i src_5 =
            _mm_unpackhi_epi16(*(__m128i *)(data + 4 * im_stride),
                               *(__m128i *)(data + 5 * im_stride));
        const __m128i src_7 =
            _mm_unpackhi_epi16(*(__m128i *)(data + 6 * im_stride),
                               *(__m128i *)(data + 7 * im_stride));

        const __m128i res_1 = _mm_madd_epi16(src_1, coeff_01);
        const __m128i res_3 = _mm_madd_epi16(src_3, coeff_23);
        const __m128i res_5 = _mm_madd_epi16(src_5, coeff_45);
        const __m128i res_7 = _mm_madd_epi16(src_7, coeff_67);

        const __m128i res_odd = _mm_add_epi32(_mm_add_epi32(res_1, res_3),
                                              _mm_add_epi32(res_5, res_7));

        // Rearrange pixels back into the order 0 ... 7
        const __m128i res_lo = _mm_unpacklo_epi32(res_even, res_odd);
        const __m128i res_hi = _mm_unpackhi_epi32(res_even, res_odd);

        const __m128i res_lo_round =
            _mm_sra_epi32(_mm_add_epi32(res_lo, round_const), round_shift);
        const __m128i res_hi_round =
            _mm_sra_epi32(_mm_add_epi32(res_hi, round_const), round_shift);

        const __m128i res_16b = _mm_packs_epi32(res_lo_round, res_hi_round);
        const __m128i res_unsigned = _mm_add_epi16(res_16b, offset_const);

        // Accumulate values into the destination buffer
        if (do_average) {
          const __m128i data_ref_0 =
              _mm_loadu_si128((__m128i *)(&dst[i * dst_stride + j]));

          const __m128i comp_avg_res =
              comp_avg(&data_ref_0, &res_unsigned, &wt, use_wtd_comp_avg);

          const __m128i round_result = convolve_rounding(
              &comp_avg_res, &offset_const, &rounding_const, rounding_shift);

          const __m128i res_8 = _mm_packus_epi16(round_result, round_result);

          if (w > 4)
            _mm_storel_epi64((__m128i *)(&dst0[i * dst_stride0 + j]), res_8);
          else
            *(uint32_t *)(&dst0[i * dst_stride0 + j]) =
                _mm_cvtsi128_si32(res_8);
        } else {
          _mm_store_si128((__m128i *)(&dst[i * dst_stride + j]), res_unsigned);
        }
      }
    }
  }
}