/*

 * 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 <emmintrin.h>

#include "av1/common/cfl.h"

#include "config/av1_rtcd.h"

static inline __m128i fill_sum_epi32(__m128i l0) {

  l0 = _mm_add_epi32(l0, _mm_shuffle_epi32(l0, _MM_SHUFFLE(1, 0, 3, 2)));

  return _mm_add_epi32(l0, _mm_shuffle_epi32(l0, _MM_SHUFFLE(2, 3, 0, 1)));

}

static inline void subtract_average_sse2(const uint16_t *src_ptr,

                                         int16_t *dst_ptr, int width,

                                         int height, int round_offset,

                                         int num_pel_log2) {

  const __m128i zeros = _mm_setzero_si128();

  const __m128i round_offset_epi32 = _mm_set1_epi32(round_offset);

  const __m128i *src = (__m128i *)src_ptr;

  const __m128i *const end = src + height * CFL_BUF_LINE_I128;

  const int step = CFL_BUF_LINE_I128 * (1 + (width == 8) + 3 * (width == 4));

  __m128i sum = zeros;

  do {

    __m128i l0;

    if (width == 4) {

      l0 = _mm_add_epi16(_mm_loadl_epi64(src),

                         _mm_loadl_epi64(src + CFL_BUF_LINE_I128));

      __m128i l1 = _mm_add_epi16(_mm_loadl_epi64(src + 2 * CFL_BUF_LINE_I128),

                                 _mm_loadl_epi64(src + 3 * CFL_BUF_LINE_I128));

      sum = _mm_add_epi32(sum, _mm_add_epi32(_mm_unpacklo_epi16(l0, zeros),

                                             _mm_unpacklo_epi16(l1, zeros)));

    } else {

      if (width == 8) {

        l0 = _mm_add_epi16(_mm_loadu_si128(src),

                           _mm_loadu_si128(src + CFL_BUF_LINE_I128));

      } else {

        l0 = _mm_add_epi16(_mm_loadu_si128(src), _mm_loadu_si128(src + 1));

      }

      sum = _mm_add_epi32(sum, _mm_add_epi32(_mm_unpacklo_epi16(l0, zeros),

                                             _mm_unpackhi_epi16(l0, zeros)));

      if (width == 32) {

        l0 = _mm_add_epi16(_mm_loadu_si128(src + 2), _mm_loadu_si128(src + 3));

        sum = _mm_add_epi32(sum, _mm_add_epi32(_mm_unpacklo_epi16(l0, zeros),

                                               _mm_unpackhi_epi16(l0, zeros)));

      }

    }

    src += step;

  } while (src < end);

  sum = fill_sum_epi32(sum);

  __m128i avg_epi16 =

      _mm_srli_epi32(_mm_add_epi32(sum, round_offset_epi32), num_pel_log2);

  avg_epi16 = _mm_packs_epi32(avg_epi16, avg_epi16);

  src = (__m128i *)src_ptr;

  __m128i *dst = (__m128i *)dst_ptr;

  do {

    if (width == 4) {

      _mm_storel_epi64(dst, _mm_sub_epi16(_mm_loadl_epi64(src), avg_epi16));

    } else {

      _mm_storeu_si128(dst, _mm_sub_epi16(_mm_loadu_si128(src), avg_epi16));

      if (width > 8) {

        _mm_storeu_si128(dst + 1,

                         _mm_sub_epi16(_mm_loadu_si128(src + 1), avg_epi16));

        if (width == 32) {

          _mm_storeu_si128(dst + 2,

                           _mm_sub_epi16(_mm_loadu_si128(src + 2), avg_epi16));

          _mm_storeu_si128(dst + 3,

                           _mm_sub_epi16(_mm_loadu_si128(src + 3), avg_epi16));

        }

      }

    }

    src += CFL_BUF_LINE_I128;

    dst += CFL_BUF_LINE_I128;

  } while (src < end);

}

CFL_SUB_AVG_FN(sse2)