/*
 * 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 <arm_neon.h>

#include "common/tools_common.h"

#include "config/aom_config.h"
#include "config/aom_dsp_rtcd.h"

#include "aom/aom_integer.h"

static INLINE void highbd_dc_predictor(uint16_t *dst, ptrdiff_t stride, int bw,
                                       const uint16_t *above,
                                       const uint16_t *left) {
  assert(bw >= 4);
  assert(IS_POWER_OF_TWO(bw));
  int expected_dc, sum = 0;
  const int count = bw * 2;
  uint32x4_t sum_q = vdupq_n_u32(0);
  uint32x2_t sum_d;
  uint16_t *dst_1;
  if (bw >= 8) {
    for (int i = 0; i < bw; i += 8) {
      sum_q = vpadalq_u16(sum_q, vld1q_u16(above));
      sum_q = vpadalq_u16(sum_q, vld1q_u16(left));
      above += 8;
      left += 8;
    }
    sum_d = vadd_u32(vget_low_u32(sum_q), vget_high_u32(sum_q));
    sum = vget_lane_s32(vreinterpret_s32_u64(vpaddl_u32(sum_d)), 0);
    expected_dc = (sum + (count >> 1)) / count;
    const uint16x8_t dc = vdupq_n_u16((uint16_t)expected_dc);
    for (int r = 0; r < bw; r++) {
      dst_1 = dst;
      for (int i = 0; i < bw; i += 8) {
        vst1q_u16(dst_1, dc);
        dst_1 += 8;
      }
      dst += stride;
    }
  } else {  // 4x4
    sum_q = vaddl_u16(vld1_u16(above), vld1_u16(left));
    sum_d = vadd_u32(vget_low_u32(sum_q), vget_high_u32(sum_q));
    sum = vget_lane_s32(vreinterpret_s32_u64(vpaddl_u32(sum_d)), 0);
    expected_dc = (sum + (count >> 1)) / count;
    const uint16x4_t dc = vdup_n_u16((uint16_t)expected_dc);
    for (int r = 0; r < bw; r++) {
      vst1_u16(dst, dc);
      dst += stride;
    }
  }
}

#define intra_pred_highbd_sized_neon(type, width)               \
  void aom_highbd_##type##_predictor_##width##x##width##_neon(  \
      uint16_t *dst, ptrdiff_t stride, const uint16_t *above,   \
      const uint16_t *left, int bd) {                           \
    (void)bd;                                                   \
    highbd_##type##_predictor(dst, stride, width, above, left); \
  }

#define intra_pred_square(type)           \
  intra_pred_highbd_sized_neon(type, 4);  \
  intra_pred_highbd_sized_neon(type, 8);  \
  intra_pred_highbd_sized_neon(type, 16); \
  intra_pred_highbd_sized_neon(type, 32); \
  intra_pred_highbd_sized_neon(type, 64);

intra_pred_square(dc);
#undef intra_pred_square

/* clang-format on */