text: /*
   *  Copyright (c) 2020, Alliance for Open Media. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree. An additional intellectual property rights grant can be found
   *  in the file PATENTS.  All contributing project authors may
   *  be found in the AUTHORS file in the root of the source tree.
   */
  
  #include <arm_neon.h>
  
  #include "config/aom_dsp_rtcd.h"
  #include "aom/aom_integer.h"
  #include "aom_dsp/arm/mem_neon.h"
  #include "aom_dsp/arm/sum_neon.h"
  #include "aom_dsp/arm/transpose_neon.h"
  
  static INLINE void sse_w16_neon(uint32x4_t *sum, const uint8_t *a,
                                  const uint8_t *b) {
    const uint8x16_t v_a0 = vld1q_u8(a);
    const uint8x16_t v_b0 = vld1q_u8(b);
    const uint8x16_t diff = vabdq_u8(v_a0, v_b0);
    const uint8x8_t diff_lo = vget_low_u8(diff);
    const uint8x8_t diff_hi = vget_high_u8(diff);
    *sum = vpadalq_u16(*sum, vmull_u8(diff_lo, diff_lo));
    *sum = vpadalq_u16(*sum, vmull_u8(diff_hi, diff_hi));
  }
  static INLINE void aom_sse4x2_neon(const uint8_t *a, int a_stride,
                                     const uint8_t *b, int b_stride,
                                     uint32x4_t *sum) {
    uint8x8_t v_a0, v_b0;
    v_a0 = v_b0 = vcreate_u8(0);
    // above line is only to shadow [-Werror=uninitialized]
    v_a0 = vreinterpret_u8_u32(
        vld1_lane_u32((uint32_t *)a, vreinterpret_u32_u8(v_a0), 0));
    v_a0 = vreinterpret_u8_u32(
        vld1_lane_u32((uint32_t *)(a + a_stride), vreinterpret_u32_u8(v_a0), 1));
    v_b0 = vreinterpret_u8_u32(
        vld1_lane_u32((uint32_t *)b, vreinterpret_u32_u8(v_b0), 0));
    v_b0 = vreinterpret_u8_u32(
        vld1_lane_u32((uint32_t *)(b + b_stride), vreinterpret_u32_u8(v_b0), 1));
    const uint8x8_t v_a_w = vabd_u8(v_a0, v_b0);
    *sum = vpadalq_u16(*sum, vmull_u8(v_a_w, v_a_w));
  }
  static INLINE void aom_sse8_neon(const uint8_t *a, const uint8_t *b,
                                   uint32x4_t *sum) {
    const uint8x8_t v_a_w = vld1_u8(a);
    const uint8x8_t v_b_w = vld1_u8(b);
    const uint8x8_t v_d_w = vabd_u8(v_a_w, v_b_w);
    *sum = vpadalq_u16(*sum, vmull_u8(v_d_w, v_d_w));
  }
  int64_t aom_sse_neon(const uint8_t *a, int a_stride, const uint8_t *b,
                       int b_stride, int width, int height) {
    int y = 0;
    int64_t sse = 0;
    uint32x4_t sum = vdupq_n_u32(0);
    switch (width) {
      case 4:
        do {
          aom_sse4x2_neon(a, a_stride, b, b_stride, &sum);
          a += a_stride << 1;
          b += b_stride << 1;
          y += 2;
        } while (y < height);
  #if defined(__aarch64__)
        sse = vaddvq_u32(sum);
  #else
        sse = horizontal_add_s32x4(vreinterpretq_s32_u32(sum));
  #endif  // __aarch64__
        break;
      case 8:
        do {
          aom_sse8_neon(a, b, &sum);
          a += a_stride;
          b += b_stride;
          y += 1;
        } while (y < height);
  #if defined(__aarch64__)
        sse = vaddvq_u32(sum);
  #else
        sse = horizontal_add_s32x4(vreinterpretq_s32_u32(sum));
  #endif  // __aarch64__
        break;
      case 16:
        do {
          sse_w16_neon(&sum, a, b);
          a += a_stride;
          b += b_stride;
          y += 1;
        } while (y < height);
  #if defined(__aarch64__)
        sse = vaddvq_u32(sum);
  #else
        sse = horizontal_add_s32x4(vreinterpretq_s32_u32(sum));
  #endif  // __aarch64__
        break;
      case 32:
        do {
          sse_w16_neon(&sum, a, b);
          sse_w16_neon(&sum, a + 16, b + 16);
          a += a_stride;
          b += b_stride;
          y += 1;
        } while (y < height);
  #if defined(__aarch64__)
        sse = vaddvq_u32(sum);
  #else
        sse = horizontal_add_s32x4(vreinterpretq_s32_u32(sum));
  #endif  // __aarch64__
        break;
      case 64:
        do {
          sse_w16_neon(&sum, a, b);
          sse_w16_neon(&sum, a + 16 * 1, b + 16 * 1);
          sse_w16_neon(&sum, a + 16 * 2, b + 16 * 2);
          sse_w16_neon(&sum, a + 16 * 3, b + 16 * 3);
          a += a_stride;
          b += b_stride;
          y += 1;
        } while (y < height);
  #if defined(__aarch64__)
        sse = vaddvq_u32(sum);
  #else
        sse = horizontal_add_s32x4(vreinterpretq_s32_u32(sum));
  #endif  // __aarch64__
        break;
      case 128:
        do {
          sse_w16_neon(&sum, a, b);
          sse_w16_neon(&sum, a + 16 * 1, b + 16 * 1);
          sse_w16_neon(&sum, a + 16 * 2, b + 16 * 2);
          sse_w16_neon(&sum, a + 16 * 3, b + 16 * 3);
          sse_w16_neon(&sum, a + 16 * 4, b + 16 * 4);
          sse_w16_neon(&sum, a + 16 * 5, b + 16 * 5);
          sse_w16_neon(&sum, a + 16 * 6, b + 16 * 6);
          sse_w16_neon(&sum, a + 16 * 7, b + 16 * 7);
          a += a_stride;
          b += b_stride;
          y += 1;
        } while (y < height);
  #if defined(__aarch64__)
        sse = vaddvq_u32(sum);
  #else
        sse = horizontal_add_s32x4(vreinterpretq_s32_u32(sum));
  #endif  // __aarch64__
        break;
      default:
        if (width & 0x07) {
          do {
            int i = 0;
            do {
              aom_sse8_neon(a + i, b + i, &sum);
              aom_sse8_neon(a + i + a_stride, b + i + b_stride, &sum);
              i += 8;
            } while (i + 4 < width);
            aom_sse4x2_neon(a + i, a_stride, b + i, b_stride, &sum);
            a += (a_stride << 1);
            b += (b_stride << 1);
            y += 2;
          } while (y < height);
        } else {
          do {
            int i = 0;
            do {
              aom_sse8_neon(a + i, b + i, &sum);
              i += 8;
            } while (i < width);
            a += a_stride;
            b += b_stride;
            y += 1;
          } while (y < height);
        }
  #if defined(__aarch64__)
        sse = vaddvq_u32(sum);
  #else
        sse = horizontal_add_s32x4(vreinterpretq_s32_u32(sum));
  #endif  // __aarch64__
        break;
    }
    return sse;
  }
  
  #if CONFIG_AV1_HIGHBITDEPTH
  static INLINE uint32_t highbd_sse_W8x1_neon(uint16x8_t q2, uint16x8_t q3) {
    uint32_t sse;
    const uint32_t sse1 = 0;
    const uint32x4_t q1 = vld1q_dup_u32(&sse1);
  
    uint16x8_t q4 = vabdq_u16(q2, q3);  // diff = abs(a[x] - b[x])
    uint16x4_t d0 = vget_low_u16(q4);
    uint16x4_t d1 = vget_high_u16(q4);
  
    uint32x4_t q6 = vmlal_u16(q1, d0, d0);
    uint32x4_t q7 = vmlal_u16(q1, d1, d1);
  
    uint32x2_t d4 = vadd_u32(vget_low_u32(q6), vget_high_u32(q6));
    uint32x2_t d5 = vadd_u32(vget_low_u32(q7), vget_high_u32(q7));
  
    uint32x2_t d6 = vadd_u32(d4, d5);
  
    sse = vget_lane_u32(d6, 0);
    sse += vget_lane_u32(d6, 1);
  
    return sse;
  }
  
  int64_t aom_highbd_sse_neon(const uint8_t *a8, int a_stride, const uint8_t *b8,
                              int b_stride, int width, int height) {
    const uint16x8_t q0 = { 0, 1, 2, 3, 4, 5, 6, 7 };
    int64_t sse = 0;
    uint16_t *a = CONVERT_TO_SHORTPTR(a8);
    uint16_t *b = CONVERT_TO_SHORTPTR(b8);
    int x, y;
    int addinc;
    uint16x4_t d0, d1, d2, d3;
    uint16_t dx;
    uint16x8_t q2, q3, q4, q5;
  
    switch (width) {
      case 4:
        for (y = 0; y < height; y += 2) {
          d0 = vld1_u16(a);  // load 4 data
          a += a_stride;
          d1 = vld1_u16(a);
          a += a_stride;
  
          d2 = vld1_u16(b);
          b += b_stride;
          d3 = vld1_u16(b);
          b += b_stride;
          q2 = vcombine_u16(d0, d1);  // make a 8 data vector
          q3 = vcombine_u16(d2, d3);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
        }
        break;
      case 8:
        for (y = 0; y < height; y++) {
          q2 = vld1q_u16(a);
          q3 = vld1q_u16(b);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          a += a_stride;
          b += b_stride;
        }
        break;
      case 16:
        for (y = 0; y < height; y++) {
          q2 = vld1q_u16(a);
          q3 = vld1q_u16(b);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 8);
          q3 = vld1q_u16(b + 8);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          a += a_stride;
          b += b_stride;
        }
        break;
      case 32:
        for (y = 0; y < height; y++) {
          q2 = vld1q_u16(a);
          q3 = vld1q_u16(b);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 8);
          q3 = vld1q_u16(b + 8);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 16);
          q3 = vld1q_u16(b + 16);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 24);
          q3 = vld1q_u16(b + 24);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          a += a_stride;
          b += b_stride;
        }
        break;
      case 64:
        for (y = 0; y < height; y++) {
          q2 = vld1q_u16(a);
          q3 = vld1q_u16(b);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 8);
          q3 = vld1q_u16(b + 8);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 16);
          q3 = vld1q_u16(b + 16);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 24);
          q3 = vld1q_u16(b + 24);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 32);
          q3 = vld1q_u16(b + 32);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 40);
          q3 = vld1q_u16(b + 40);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 48);
          q3 = vld1q_u16(b + 48);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 56);
          q3 = vld1q_u16(b + 56);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          a += a_stride;
          b += b_stride;
        }
        break;
      case 128:
        for (y = 0; y < height; y++) {
          q2 = vld1q_u16(a);
          q3 = vld1q_u16(b);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 8);
          q3 = vld1q_u16(b + 8);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 16);
          q3 = vld1q_u16(b + 16);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 24);
          q3 = vld1q_u16(b + 24);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 32);
          q3 = vld1q_u16(b + 32);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 40);
          q3 = vld1q_u16(b + 40);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 48);
          q3 = vld1q_u16(b + 48);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 56);
          q3 = vld1q_u16(b + 56);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 64);
          q3 = vld1q_u16(b + 64);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 72);
          q3 = vld1q_u16(b + 72);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 80);
          q3 = vld1q_u16(b + 80);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 88);
          q3 = vld1q_u16(b + 88);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 96);
          q3 = vld1q_u16(b + 96);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 104);
          q3 = vld1q_u16(b + 104);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 112);
          q3 = vld1q_u16(b + 112);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
  
          q2 = vld1q_u16(a + 120);
          q3 = vld1q_u16(b + 120);
  
          sse += highbd_sse_W8x1_neon(q2, q3);
          a += a_stride;
          b += b_stride;
        }
        break;
      default:
  
        for (y = 0; y < height; y++) {
          x = width;
          while (x > 0) {
            addinc = width - x;
            q2 = vld1q_u16(a + addinc);
            q3 = vld1q_u16(b + addinc);
            if (x < 8) {
              dx = x;
              q4 = vld1q_dup_u16(&dx);
              q5 = vcltq_u16(q0, q4);
              q2 = vandq_u16(q2, q5);
              q3 = vandq_u16(q3, q5);
            }
            sse += highbd_sse_W8x1_neon(q2, q3);
            x -= 8;
          }
          a += a_stride;
          b += b_stride;
        }
    }
    return (int64_t)sse;
  }
  #endif
  