/*

 * 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"

static inline void subtract32_avx2(int16_t *diff_ptr, const uint8_t *src_ptr,

                                   const uint8_t *pred_ptr) {

  __m256i s = _mm256_lddqu_si256((__m256i *)(src_ptr));

  __m256i p = _mm256_lddqu_si256((__m256i *)(pred_ptr));

  __m256i set_one_minusone = _mm256_set1_epi32((int)0xff01ff01);

  __m256i diff0 = _mm256_unpacklo_epi8(s, p);

  __m256i diff1 = _mm256_unpackhi_epi8(s, p);

  diff0 = _mm256_maddubs_epi16(diff0, set_one_minusone);

  diff1 = _mm256_maddubs_epi16(diff1, set_one_minusone);

  _mm256_store_si256((__m256i *)(diff_ptr),

                     _mm256_permute2x128_si256(diff0, diff1, 0x20));

  _mm256_store_si256((__m256i *)(diff_ptr + 16),

                     _mm256_permute2x128_si256(diff0, diff1, 0x31));

}

static inline void subtract_block_16xn_avx2(

    int rows, int16_t *diff_ptr, ptrdiff_t diff_stride, const uint8_t *src_ptr,

    ptrdiff_t src_stride, const uint8_t *pred_ptr, ptrdiff_t pred_stride) {

  for (int32_t j = 0; j < rows; ++j) {

    __m128i s = _mm_lddqu_si128((__m128i *)(src_ptr));

    __m128i p = _mm_lddqu_si128((__m128i *)(pred_ptr));

    __m256i s_0 = _mm256_cvtepu8_epi16(s);

    __m256i p_0 = _mm256_cvtepu8_epi16(p);

    const __m256i d_0 = _mm256_sub_epi16(s_0, p_0);

    _mm256_store_si256((__m256i *)(diff_ptr), d_0);

    src_ptr += src_stride;

    pred_ptr += pred_stride;

    diff_ptr += diff_stride;

  }

}

static inline void subtract_block_32xn_avx2(

    int rows, int16_t *diff_ptr, ptrdiff_t diff_stride, const uint8_t *src_ptr,

    ptrdiff_t src_stride, const uint8_t *pred_ptr, ptrdiff_t pred_stride) {

  for (int32_t j = 0; j < rows; ++j) {

    subtract32_avx2(diff_ptr, src_ptr, pred_ptr);

    src_ptr += src_stride;

    pred_ptr += pred_stride;

    diff_ptr += diff_stride;

  }

}

static inline void subtract_block_64xn_avx2(

    int rows, int16_t *diff_ptr, ptrdiff_t diff_stride, const uint8_t *src_ptr,

    ptrdiff_t src_stride, const uint8_t *pred_ptr, ptrdiff_t pred_stride) {

  for (int32_t j = 0; j < rows; ++j) {

    subtract32_avx2(diff_ptr, src_ptr, pred_ptr);

    subtract32_avx2(diff_ptr + 32, src_ptr + 32, pred_ptr + 32);

    src_ptr += src_stride;

    pred_ptr += pred_stride;

    diff_ptr += diff_stride;

  }

}

static inline void subtract_block_128xn_avx2(

    int rows, int16_t *diff_ptr, ptrdiff_t diff_stride, const uint8_t *src_ptr,

    ptrdiff_t src_stride, const uint8_t *pred_ptr, ptrdiff_t pred_stride) {

  for (int32_t j = 0; j < rows; ++j) {

    subtract32_avx2(diff_ptr, src_ptr, pred_ptr);

    subtract32_avx2(diff_ptr + 32, src_ptr + 32, pred_ptr + 32);

    subtract32_avx2(diff_ptr + 64, src_ptr + 64, pred_ptr + 64);

    subtract32_avx2(diff_ptr + 96, src_ptr + 96, pred_ptr + 96);

    src_ptr += src_stride;

    pred_ptr += pred_stride;

    diff_ptr += diff_stride;

  }

}

void aom_subtract_block_avx2(int rows, int cols, int16_t *diff_ptr,

                             ptrdiff_t diff_stride, const uint8_t *src_ptr,

                             ptrdiff_t src_stride, const uint8_t *pred_ptr,

                             ptrdiff_t pred_stride) {

  switch (cols) {

    case 16:

      subtract_block_16xn_avx2(rows, diff_ptr, diff_stride, src_ptr, src_stride,

                               pred_ptr, pred_stride);

      break;

    case 32:

      subtract_block_32xn_avx2(rows, diff_ptr, diff_stride, src_ptr, src_stride,

                               pred_ptr, pred_stride);

      break;

    case 64:

      subtract_block_64xn_avx2(rows, diff_ptr, diff_stride, src_ptr, src_stride,

                               pred_ptr, pred_stride);

      break;

    case 128:

      subtract_block_128xn_avx2(rows, diff_ptr, diff_stride, src_ptr,

                                src_stride, pred_ptr, pred_stride);

      break;

    default:

      aom_subtract_block_sse2(rows, cols, diff_ptr, diff_stride, src_ptr,

                              src_stride, pred_ptr, pred_stride);

      break;

  }

}