/*
 * Copyright (c) 2016, 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 <arm_neon.h>

#include "./aom_config.h"
#include "./aom_dsp_rtcd.h"
#include "aom/aom_integer.h"

static INLINE unsigned int horizontal_long_add_16x8(const uint16x8_t vec_lo,
                                                    const uint16x8_t vec_hi) {
  const uint32x4_t vec_l_lo =
      vaddl_u16(vget_low_u16(vec_lo), vget_high_u16(vec_lo));
  const uint32x4_t vec_l_hi =
      vaddl_u16(vget_low_u16(vec_hi), vget_high_u16(vec_hi));
  const uint32x4_t a = vaddq_u32(vec_l_lo, vec_l_hi);
  const uint64x2_t b = vpaddlq_u32(a);
  const uint32x2_t c = vadd_u32(vreinterpret_u32_u64(vget_low_u64(b)),
                                vreinterpret_u32_u64(vget_high_u64(b)));
  return vget_lane_u32(c, 0);
}

// Calculate the absolute difference of 64 bytes from vec_src_00, vec_src_16,
// vec_src_32, vec_src_48 and ref. Accumulate partial sums in vec_sum_ref_lo
// and vec_sum_ref_hi.
static void sad_neon_64(const uint8x16_t vec_src_00,
                        const uint8x16_t vec_src_16,
                        const uint8x16_t vec_src_32,
                        const uint8x16_t vec_src_48, const uint8_t *ref,
                        uint16x8_t *vec_sum_ref_lo,
                        uint16x8_t *vec_sum_ref_hi) {
  const uint8x16_t vec_ref_00 = vld1q_u8(ref);
  const uint8x16_t vec_ref_16 = vld1q_u8(ref + 16);
  const uint8x16_t vec_ref_32 = vld1q_u8(ref + 32);
  const uint8x16_t vec_ref_48 = vld1q_u8(ref + 48);

  *vec_sum_ref_lo = vabal_u8(*vec_sum_ref_lo, vget_low_u8(vec_src_00),
                             vget_low_u8(vec_ref_00));
  *vec_sum_ref_hi = vabal_u8(*vec_sum_ref_hi, vget_high_u8(vec_src_00),
                             vget_high_u8(vec_ref_00));
  *vec_sum_ref_lo = vabal_u8(*vec_sum_ref_lo, vget_low_u8(vec_src_16),
                             vget_low_u8(vec_ref_16));
  *vec_sum_ref_hi = vabal_u8(*vec_sum_ref_hi, vget_high_u8(vec_src_16),
                             vget_high_u8(vec_ref_16));
  *vec_sum_ref_lo = vabal_u8(*vec_sum_ref_lo, vget_low_u8(vec_src_32),
                             vget_low_u8(vec_ref_32));
  *vec_sum_ref_hi = vabal_u8(*vec_sum_ref_hi, vget_high_u8(vec_src_32),
                             vget_high_u8(vec_ref_32));
  *vec_sum_ref_lo = vabal_u8(*vec_sum_ref_lo, vget_low_u8(vec_src_48),
                             vget_low_u8(vec_ref_48));
  *vec_sum_ref_hi = vabal_u8(*vec_sum_ref_hi, vget_high_u8(vec_src_48),
                             vget_high_u8(vec_ref_48));
}

// Calculate the absolute difference of 32 bytes from vec_src_00, vec_src_16,
// and ref. Accumulate partial sums in vec_sum_ref_lo and vec_sum_ref_hi.
static void sad_neon_32(const uint8x16_t vec_src_00,
                        const uint8x16_t vec_src_16, const uint8_t *ref,
                        uint16x8_t *vec_sum_ref_lo,
                        uint16x8_t *vec_sum_ref_hi) {
  const uint8x16_t vec_ref_00 = vld1q_u8(ref);
  const uint8x16_t vec_ref_16 = vld1q_u8(ref + 16);

  *vec_sum_ref_lo = vabal_u8(*vec_sum_ref_lo, vget_low_u8(vec_src_00),
                             vget_low_u8(vec_ref_00));
  *vec_sum_ref_hi = vabal_u8(*vec_sum_ref_hi, vget_high_u8(vec_src_00),
                             vget_high_u8(vec_ref_00));
  *vec_sum_ref_lo = vabal_u8(*vec_sum_ref_lo, vget_low_u8(vec_src_16),
                             vget_low_u8(vec_ref_16));
  *vec_sum_ref_hi = vabal_u8(*vec_sum_ref_hi, vget_high_u8(vec_src_16),
                             vget_high_u8(vec_ref_16));
}

void aom_sad64x64x4d_neon(const uint8_t *src, int src_stride,
                          const uint8_t *const ref[4], int ref_stride,
                          uint32_t *res) {
  int i;
  uint16x8_t vec_sum_ref0_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref0_hi = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref1_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref1_hi = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref2_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref2_hi = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref3_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref3_hi = vdupq_n_u16(0);
  const uint8_t *ref0, *ref1, *ref2, *ref3;
  ref0 = ref[0];
  ref1 = ref[1];
  ref2 = ref[2];
  ref3 = ref[3];

  for (i = 0; i < 64; ++i) {
    const uint8x16_t vec_src_00 = vld1q_u8(src);
    const uint8x16_t vec_src_16 = vld1q_u8(src + 16);
    const uint8x16_t vec_src_32 = vld1q_u8(src + 32);
    const uint8x16_t vec_src_48 = vld1q_u8(src + 48);

    sad_neon_64(vec_src_00, vec_src_16, vec_src_32, vec_src_48, ref0,
                &vec_sum_ref0_lo, &vec_sum_ref0_hi);
    sad_neon_64(vec_src_00, vec_src_16, vec_src_32, vec_src_48, ref1,
                &vec_sum_ref1_lo, &vec_sum_ref1_hi);
    sad_neon_64(vec_src_00, vec_src_16, vec_src_32, vec_src_48, ref2,
                &vec_sum_ref2_lo, &vec_sum_ref2_hi);
    sad_neon_64(vec_src_00, vec_src_16, vec_src_32, vec_src_48, ref3,
                &vec_sum_ref3_lo, &vec_sum_ref3_hi);

    src += src_stride;
    ref0 += ref_stride;
    ref1 += ref_stride;
    ref2 += ref_stride;
    ref3 += ref_stride;
  }

  res[0] = horizontal_long_add_16x8(vec_sum_ref0_lo, vec_sum_ref0_hi);
  res[1] = horizontal_long_add_16x8(vec_sum_ref1_lo, vec_sum_ref1_hi);
  res[2] = horizontal_long_add_16x8(vec_sum_ref2_lo, vec_sum_ref2_hi);
  res[3] = horizontal_long_add_16x8(vec_sum_ref3_lo, vec_sum_ref3_hi);
}

void aom_sad32x32x4d_neon(const uint8_t *src, int src_stride,
                          const uint8_t *const ref[4], int ref_stride,
                          uint32_t *res) {
  int i;
  uint16x8_t vec_sum_ref0_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref0_hi = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref1_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref1_hi = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref2_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref2_hi = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref3_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref3_hi = vdupq_n_u16(0);
  const uint8_t *ref0, *ref1, *ref2, *ref3;
  ref0 = ref[0];
  ref1 = ref[1];
  ref2 = ref[2];
  ref3 = ref[3];

  for (i = 0; i < 32; ++i) {
    const uint8x16_t vec_src_00 = vld1q_u8(src);
    const uint8x16_t vec_src_16 = vld1q_u8(src + 16);

    sad_neon_32(vec_src_00, vec_src_16, ref0, &vec_sum_ref0_lo,
                &vec_sum_ref0_hi);
    sad_neon_32(vec_src_00, vec_src_16, ref1, &vec_sum_ref1_lo,
                &vec_sum_ref1_hi);
    sad_neon_32(vec_src_00, vec_src_16, ref2, &vec_sum_ref2_lo,
                &vec_sum_ref2_hi);
    sad_neon_32(vec_src_00, vec_src_16, ref3, &vec_sum_ref3_lo,
                &vec_sum_ref3_hi);

    src += src_stride;
    ref0 += ref_stride;
    ref1 += ref_stride;
    ref2 += ref_stride;
    ref3 += ref_stride;
  }

  res[0] = horizontal_long_add_16x8(vec_sum_ref0_lo, vec_sum_ref0_hi);
  res[1] = horizontal_long_add_16x8(vec_sum_ref1_lo, vec_sum_ref1_hi);
  res[2] = horizontal_long_add_16x8(vec_sum_ref2_lo, vec_sum_ref2_hi);
  res[3] = horizontal_long_add_16x8(vec_sum_ref3_lo, vec_sum_ref3_hi);
}

void aom_sad16x16x4d_neon(const uint8_t *src, int src_stride,
                          const uint8_t *const ref[4], int ref_stride,
                          uint32_t *res) {
  int i;
  uint16x8_t vec_sum_ref0_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref0_hi = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref1_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref1_hi = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref2_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref2_hi = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref3_lo = vdupq_n_u16(0);
  uint16x8_t vec_sum_ref3_hi = vdupq_n_u16(0);
  const uint8_t *ref0, *ref1, *ref2, *ref3;
  ref0 = ref[0];
  ref1 = ref[1];
  ref2 = ref[2];
  ref3 = ref[3];

  for (i = 0; i < 16; ++i) {
    const uint8x16_t vec_src = vld1q_u8(src);
    const uint8x16_t vec_ref0 = vld1q_u8(ref0);
    const uint8x16_t vec_ref1 = vld1q_u8(ref1);
    const uint8x16_t vec_ref2 = vld1q_u8(ref2);
    const uint8x16_t vec_ref3 = vld1q_u8(ref3);

    vec_sum_ref0_lo =
        vabal_u8(vec_sum_ref0_lo, vget_low_u8(vec_src), vget_low_u8(vec_ref0));
    vec_sum_ref0_hi = vabal_u8(vec_sum_ref0_hi, vget_high_u8(vec_src),
                               vget_high_u8(vec_ref0));
    vec_sum_ref1_lo =
        vabal_u8(vec_sum_ref1_lo, vget_low_u8(vec_src), vget_low_u8(vec_ref1));
    vec_sum_ref1_hi = vabal_u8(vec_sum_ref1_hi, vget_high_u8(vec_src),
                               vget_high_u8(vec_ref1));
    vec_sum_ref2_lo =
        vabal_u8(vec_sum_ref2_lo, vget_low_u8(vec_src), vget_low_u8(vec_ref2));
    vec_sum_ref2_hi = vabal_u8(vec_sum_ref2_hi, vget_high_u8(vec_src),
                               vget_high_u8(vec_ref2));
    vec_sum_ref3_lo =
        vabal_u8(vec_sum_ref3_lo, vget_low_u8(vec_src), vget_low_u8(vec_ref3));
    vec_sum_ref3_hi = vabal_u8(vec_sum_ref3_hi, vget_high_u8(vec_src),
                               vget_high_u8(vec_ref3));

    src += src_stride;
    ref0 += ref_stride;
    ref1 += ref_stride;
    ref2 += ref_stride;
    ref3 += ref_stride;
  }

  res[0] = horizontal_long_add_16x8(vec_sum_ref0_lo, vec_sum_ref0_hi);
  res[1] = horizontal_long_add_16x8(vec_sum_ref1_lo, vec_sum_ref1_hi);
  res[2] = horizontal_long_add_16x8(vec_sum_ref2_lo, vec_sum_ref2_hi);
  res[3] = horizontal_long_add_16x8(vec_sum_ref3_lo, vec_sum_ref3_hi);
}