/*
 * 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 <smmintrin.h>
#include <immintrin.h>

#include "config/aom_dsp_rtcd.h"

#include "aom_ports/mem.h"
#include "aom_dsp/x86/synonyms.h"
#include "aom_dsp/x86/synonyms_avx2.h"

static INLINE int64_t summary_all_avx2(const __m256i *sum_all) {
  int64_t sum;
  __m256i zero = _mm256_setzero_si256();
  const __m256i sum0_4x64 = _mm256_unpacklo_epi32(*sum_all, zero);
  const __m256i sum1_4x64 = _mm256_unpackhi_epi32(*sum_all, zero);
  const __m256i sum_4x64 = _mm256_add_epi64(sum0_4x64, sum1_4x64);
  const __m128i sum_2x64 = _mm_add_epi64(_mm256_castsi256_si128(sum_4x64),
                                         _mm256_extracti128_si256(sum_4x64, 1));
  const __m128i sum_1x64 = _mm_add_epi64(sum_2x64, _mm_srli_si128(sum_2x64, 8));
  xx_storel_64(&sum, sum_1x64);
  return sum;
}

static INLINE void summary_32_avx2(const __m256i *sum32, __m256i *sum) {
  const __m256i sum0_4x64 =
      _mm256_cvtepu32_epi64(_mm256_castsi256_si128(*sum32));
  const __m256i sum1_4x64 =
      _mm256_cvtepu32_epi64(_mm256_extracti128_si256(*sum32, 1));
  const __m256i sum_4x64 = _mm256_add_epi64(sum0_4x64, sum1_4x64);
  *sum = _mm256_add_epi64(*sum, sum_4x64);
}

static INLINE int64_t summary_4x64_avx2(const __m256i sum_4x64) {
  int64_t sum;
  const __m128i sum_2x64 = _mm_add_epi64(_mm256_castsi256_si128(sum_4x64),
                                         _mm256_extracti128_si256(sum_4x64, 1));
  const __m128i sum_1x64 = _mm_add_epi64(sum_2x64, _mm_srli_si128(sum_2x64, 8));

  xx_storel_64(&sum, sum_1x64);
  return sum;
}

static INLINE void highbd_sse_w16_avx2(__m256i *sum, const uint16_t *a,
                                       const uint16_t *b) {
  const __m256i v_a_w = yy_loadu_256(a);
  const __m256i v_b_w = yy_loadu_256(b);
  const __m256i v_d_w = _mm256_sub_epi16(v_a_w, v_b_w);
  *sum = _mm256_add_epi32(*sum, _mm256_madd_epi16(v_d_w, v_d_w));
}

static INLINE void highbd_sse_w4x4_avx2(__m256i *sum, const uint16_t *a,
                                        int a_stride, const uint16_t *b,
                                        int b_stride) {
  const __m128i v_a0 = xx_loadl_64(a);
  const __m128i v_a1 = xx_loadl_64(a + a_stride);
  const __m128i v_a2 = xx_loadl_64(a + a_stride * 2);
  const __m128i v_a3 = xx_loadl_64(a + a_stride * 3);
  const __m128i v_b0 = xx_loadl_64(b);
  const __m128i v_b1 = xx_loadl_64(b + b_stride);
  const __m128i v_b2 = xx_loadl_64(b + b_stride * 2);
  const __m128i v_b3 = xx_loadl_64(b + b_stride * 3);
  const __m256i v_a_w = yy_set_m128i(_mm_unpacklo_epi64(v_a0, v_a1),
                                     _mm_unpacklo_epi64(v_a2, v_a3));
  const __m256i v_b_w = yy_set_m128i(_mm_unpacklo_epi64(v_b0, v_b1),
                                     _mm_unpacklo_epi64(v_b2, v_b3));
  const __m256i v_d_w = _mm256_sub_epi16(v_a_w, v_b_w);
  *sum = _mm256_add_epi32(*sum, _mm256_madd_epi16(v_d_w, v_d_w));
}

static INLINE void highbd_sse_w8x2_avx2(__m256i *sum, const uint16_t *a,
                                        int a_stride, const uint16_t *b,
                                        int b_stride) {
  const __m256i v_a_w = yy_loadu2_128(a + a_stride, a);
  const __m256i v_b_w = yy_loadu2_128(b + b_stride, b);
  const __m256i v_d_w = _mm256_sub_epi16(v_a_w, v_b_w);
  *sum = _mm256_add_epi32(*sum, _mm256_madd_epi16(v_d_w, v_d_w));
}
int64_t aom_highbd_sse_avx2(const uint16_t *a, int a_stride, const uint16_t *b,
                            int b_stride, int width, int height) {
  int32_t y = 0;
  int64_t sse = 0;
  __m256i sum = _mm256_setzero_si256();
  switch (width) {
    case 4:
      do {
        highbd_sse_w4x4_avx2(&sum, a, a_stride, b, b_stride);
        a += a_stride << 2;
        b += b_stride << 2;
        y += 4;
      } while (y < height);
      sse = summary_all_avx2(&sum);
      break;
    case 8:
      do {
        highbd_sse_w8x2_avx2(&sum, a, a_stride, b, b_stride);
        a += a_stride << 1;
        b += b_stride << 1;
        y += 2;
      } while (y < height);
      sse = summary_all_avx2(&sum);
      break;
    case 16:
      do {
        highbd_sse_w16_avx2(&sum, a, b);
        a += a_stride;
        b += b_stride;
        y += 1;
      } while (y < height);
      sse = summary_all_avx2(&sum);
      break;
    case 32:
      do {
        int l = 0;
        __m256i sum32 = _mm256_setzero_si256();
        do {
          highbd_sse_w16_avx2(&sum32, a, b);
          highbd_sse_w16_avx2(&sum32, a + 16, b + 16);
          a += a_stride;
          b += b_stride;
          l += 1;
        } while (l < 64 && l < (height - y));
        summary_32_avx2(&sum32, &sum);
        y += 64;
      } while (y < height);
      sse = summary_4x64_avx2(sum);
      break;
    case 64:
      do {
        int l = 0;
        __m256i sum32 = _mm256_setzero_si256();
        do {
          highbd_sse_w16_avx2(&sum32, a, b);
          highbd_sse_w16_avx2(&sum32, a + 16 * 1, b + 16 * 1);
          highbd_sse_w16_avx2(&sum32, a + 16 * 2, b + 16 * 2);
          highbd_sse_w16_avx2(&sum32, a + 16 * 3, b + 16 * 3);
          a += a_stride;
          b += b_stride;
          l += 1;
        } while (l < 32 && l < (height - y));
        summary_32_avx2(&sum32, &sum);
        y += 32;
      } while (y < height);
      sse = summary_4x64_avx2(sum);
      break;
    case 128:
      do {
        int l = 0;
        __m256i sum32 = _mm256_setzero_si256();
        do {
          highbd_sse_w16_avx2(&sum32, a, b);
          highbd_sse_w16_avx2(&sum32, a + 16 * 1, b + 16 * 1);
          highbd_sse_w16_avx2(&sum32, a + 16 * 2, b + 16 * 2);
          highbd_sse_w16_avx2(&sum32, a + 16 * 3, b + 16 * 3);
          highbd_sse_w16_avx2(&sum32, a + 16 * 4, b + 16 * 4);
          highbd_sse_w16_avx2(&sum32, a + 16 * 5, b + 16 * 5);
          highbd_sse_w16_avx2(&sum32, a + 16 * 6, b + 16 * 6);
          highbd_sse_w16_avx2(&sum32, a + 16 * 7, b + 16 * 7);
          a += a_stride;
          b += b_stride;
          l += 1;
        } while (l < 16 && l < (height - y));
        summary_32_avx2(&sum32, &sum);
        y += 16;
      } while (y < height);
      sse = summary_4x64_avx2(sum);
      break;
    default:
      if (width & 0x7) {
        do {
          int i = 0;
          __m256i sum32 = _mm256_setzero_si256();
          do {
            highbd_sse_w8x2_avx2(&sum32, a + i, a_stride, b + i, b_stride);
            const uint16_t *a2 = a + i + (a_stride << 1);
            const uint16_t *b2 = b + i + (b_stride << 1);
            highbd_sse_w8x2_avx2(&sum32, a2, a_stride, b2, b_stride);
            i += 8;
          } while (i + 4 < width);
          highbd_sse_w4x4_avx2(&sum32, a + i, a_stride, b + i, b_stride);
          summary_32_avx2(&sum32, &sum);
          a += a_stride << 2;
          b += b_stride << 2;
          y += 4;
        } while (y < height);
      } else {
        do {
          int l = 0;
          __m256i sum32 = _mm256_setzero_si256();
          do {
            int i = 0;
            do {
              highbd_sse_w8x2_avx2(&sum32, a + i, a_stride, b + i, b_stride);
              i += 8;
            } while (i < width);
            a += a_stride << 1;
            b += b_stride << 1;
            l += 2;
          } while (l < 8 && l < (height - y));
          summary_32_avx2(&sum32, &sum);
          y += 8;
        } while (y < height);
      }
      sse = summary_4x64_avx2(sum);
      break;
  }
  return sse;
}