/*

 * 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 <smmintrin.h>

#include "config/aom_config.h"

#include "config/av1_rtcd.h"

#include "av1/common/restoration.h"

#include "aom_dsp/x86/synonyms.h"

// Load 4 bytes from the possibly-misaligned pointer p, extend each byte to

// 32-bit precision and return them in an SSE register.

static __m128i xx_load_extend_8_32(const void *p) {

  return _mm_cvtepu8_epi32(xx_loadl_32(p));

}

// Load 4 halfwords from the possibly-misaligned pointer p, extend each

// halfword to 32-bit precision and return them in an SSE register.

static __m128i xx_load_extend_16_32(const void *p) {

  return _mm_cvtepu16_epi32(xx_loadl_64(p));

}

// Compute the scan of an SSE register holding 4 32-bit integers. If the

// register holds x0..x3 then the scan will hold x0, x0+x1, x0+x1+x2,

// x0+x1+x2+x3

static __m128i scan_32(__m128i x) {

  const __m128i x01 = _mm_add_epi32(x, _mm_slli_si128(x, 4));

  return _mm_add_epi32(x01, _mm_slli_si128(x01, 8));

}

// Compute two integral images from src. B sums elements; A sums their

// squares. The images are offset by one pixel, so will have width and height

// equal to width + 1, height + 1 and the first row and column will be zero.

//

// A+1 and B+1 should be aligned to 16 bytes. buf_stride should be a multiple

// of 4.

static void integral_images(const uint8_t *src, int src_stride, int width,

                            int height, int32_t *A, int32_t *B,

                            int buf_stride) {

  // Write out the zero top row

  memset(A, 0, sizeof(*A) * (width + 1));

  memset(B, 0, sizeof(*B) * (width + 1));

  const __m128i zero = _mm_setzero_si128();

  for (int i = 0; i < height; ++i) {

    // Zero the left column.

    A[(i + 1) * buf_stride] = B[(i + 1) * buf_stride] = 0;

    // ldiff is the difference H - D where H is the output sample immediately

    // to the left and D is the output sample above it. These are scalars,

    // replicated across the four lanes.

    __m128i ldiff1 = zero, ldiff2 = zero;

    for (int j = 0; j < width; j += 4) {

      const int ABj = 1 + j;

      const __m128i above1 = xx_load_128(B + ABj + i * buf_stride);

      const __m128i above2 = xx_load_128(A + ABj + i * buf_stride);

      const __m128i x1 = xx_load_extend_8_32(src + j + i * src_stride);

      const __m128i x2 = _mm_madd_epi16(x1, x1);

      const __m128i sc1 = scan_32(x1);

      const __m128i sc2 = scan_32(x2);

      const __m128i row1 = _mm_add_epi32(_mm_add_epi32(sc1, above1), ldiff1);

      const __m128i row2 = _mm_add_epi32(_mm_add_epi32(sc2, above2), ldiff2);

      xx_store_128(B + ABj + (i + 1) * buf_stride, row1);

      xx_store_128(A + ABj + (i + 1) * buf_stride, row2);

      // Calculate the new H - D.

      ldiff1 = _mm_shuffle_epi32(_mm_sub_epi32(row1, above1), 0xff);

      ldiff2 = _mm_shuffle_epi32(_mm_sub_epi32(row2, above2), 0xff);

    }

  }

}

// Compute two integral images from src. B sums elements; A sums their squares

//

// A and B should be aligned to 16 bytes. buf_stride should be a multiple of 4.

static void integral_images_highbd(const uint16_t *src, int src_stride,

                                   int width, int height, int32_t *A,

                                   int32_t *B, int buf_stride) {

  // Write out the zero top row

  memset(A, 0, sizeof(*A) * (width + 1));

  memset(B, 0, sizeof(*B) * (width + 1));

  const __m128i zero = _mm_setzero_si128();

  for (int i = 0; i < height; ++i) {

    // Zero the left column.

    A[(i + 1) * buf_stride] = B[(i + 1) * buf_stride] = 0;

    // ldiff is the difference H - D where H is the output sample immediately

    // to the left and D is the output sample above it. These are scalars,

    // replicated across the four lanes.

    __m128i ldiff1 = zero, ldiff2 = zero;

    for (int j = 0; j < width; j += 4) {

      const int ABj = 1 + j;

      const __m128i above1 = xx_load_128(B + ABj + i * buf_stride);

      const __m128i above2 = xx_load_128(A + ABj + i * buf_stride);

      const __m128i x1 = xx_load_extend_16_32(src + j + i * src_stride);

      const __m128i x2 = _mm_madd_epi16(x1, x1);

      const __m128i sc1 = scan_32(x1);

      const __m128i sc2 = scan_32(x2);

      const __m128i row1 = _mm_add_epi32(_mm_add_epi32(sc1, above1), ldiff1);

      const __m128i row2 = _mm_add_epi32(_mm_add_epi32(sc2, above2), ldiff2);

      xx_store_128(B + ABj + (i + 1) * buf_stride, row1);

      xx_store_128(A + ABj + (i + 1) * buf_stride, row2);

      // Calculate the new H - D.

      ldiff1 = _mm_shuffle_epi32(_mm_sub_epi32(row1, above1), 0xff);

      ldiff2 = _mm_shuffle_epi32(_mm_sub_epi32(row2, above2), 0xff);

    }

  }

}

// Compute 4 values of boxsum from the given integral image. ii should point

// at the middle of the box (for the first value). r is the box radius.

static inline __m128i boxsum_from_ii(const int32_t *ii, int stride, int r) {

  const __m128i tl = xx_loadu_128(ii - (r + 1) - (r + 1) * stride);

  const __m128i tr = xx_loadu_128(ii + (r + 0) - (r + 1) * stride);

  const __m128i bl = xx_loadu_128(ii - (r + 1) + r * stride);

  const __m128i br = xx_loadu_128(ii + (r + 0) + r * stride);

  const __m128i u = _mm_sub_epi32(tr, tl);

  const __m128i v = _mm_sub_epi32(br, bl);

  return _mm_sub_epi32(v, u);

}

static __m128i round_for_shift(unsigned shift) {

  return _mm_set1_epi32((1 << shift) >> 1);

}

static __m128i compute_p(__m128i sum1, __m128i sum2, int bit_depth, int n) {

  __m128i an, bb;

  if (bit_depth > 8) {

    const __m128i rounding_a = round_for_shift(2 * (bit_depth - 8));

    const __m128i rounding_b = round_for_shift(bit_depth - 8);

    const __m128i shift_a = _mm_cvtsi32_si128(2 * (bit_depth - 8));

    const __m128i shift_b = _mm_cvtsi32_si128(bit_depth - 8);

    const __m128i a = _mm_srl_epi32(_mm_add_epi32(sum2, rounding_a), shift_a);

    const __m128i b = _mm_srl_epi32(_mm_add_epi32(sum1, rounding_b), shift_b);

    // b < 2^14, so we can use a 16-bit madd rather than a 32-bit

    // mullo to square it

    bb = _mm_madd_epi16(b, b);

    an = _mm_max_epi32(_mm_mullo_epi32(a, _mm_set1_epi32(n)), bb);

  } else {

    bb = _mm_madd_epi16(sum1, sum1);

    an = _mm_mullo_epi32(sum2, _mm_set1_epi32(n));

  }

  return _mm_sub_epi32(an, bb);

}

// Assumes that C, D are integral images for the original buffer which has been

// extended to have a padding of SGRPROJ_BORDER_VERT/SGRPROJ_BORDER_HORZ pixels

// on the sides. A, B, C, D point at logical position (0, 0).

static void calc_ab(int32_t *A, int32_t *B, const int32_t *C, const int32_t *D,

                    int width, int height, int buf_stride, int bit_depth,

                    int sgr_params_idx, int radius_idx) {

  const sgr_params_type *const params = &av1_sgr_params[sgr_params_idx];

  const int r = params->r[radius_idx];

  const int n = (2 * r + 1) * (2 * r + 1);

  const __m128i s = _mm_set1_epi32(params->s[radius_idx]);

  // one_over_n[n-1] is 2^12/n, so easily fits in an int16

  const __m128i one_over_n = _mm_set1_epi32(av1_one_by_x[n - 1]);

  const __m128i rnd_z = round_for_shift(SGRPROJ_MTABLE_BITS);

  const __m128i rnd_res = round_for_shift(SGRPROJ_RECIP_BITS);

  // Set up masks

  const __m128i ones32 = _mm_set_epi32(0, 0, ~0, ~0);

  __m128i mask[4];

  for (int idx = 0; idx < 4; idx++) {

    const __m128i shift = _mm_cvtsi32_si128(8 * (4 - idx));

    mask[idx] = _mm_cvtepi8_epi32(_mm_srl_epi64(ones32, shift));

  }

  for (int i = -1; i < height + 1; ++i) {

    for (int j = -1; j < width + 1; j += 4) {

      const int32_t *Cij = C + i * buf_stride + j;

      const int32_t *Dij = D + i * buf_stride + j;

      __m128i sum1 = boxsum_from_ii(Dij, buf_stride, r);

      __m128i sum2 = boxsum_from_ii(Cij, buf_stride, r);

      // When width + 2 isn't a multiple of 4, sum1 and sum2 will contain

      // some uninitialised data in their upper words. We use a mask to

      // ensure that these bits are set to 0.

      int idx = AOMMIN(4, width + 1 - j);

      assert(idx >= 1);

      if (idx < 4) {

        sum1 = _mm_and_si128(mask[idx], sum1);

        sum2 = _mm_and_si128(mask[idx], sum2);

      }

      const __m128i p = compute_p(sum1, sum2, bit_depth, n);

      const __m128i z = _mm_min_epi32(

          _mm_srli_epi32(_mm_add_epi32(_mm_mullo_epi32(p, s), rnd_z),

                         SGRPROJ_MTABLE_BITS),

          _mm_set1_epi32(255));

      // 'Gather' type instructions are not available pre-AVX2, so synthesize a

      // gather using scalar loads.

      const __m128i a_res =

          _mm_set_epi32(av1_x_by_xplus1[_mm_extract_epi32(z, 3)],

                        av1_x_by_xplus1[_mm_extract_epi32(z, 2)],

                        av1_x_by_xplus1[_mm_extract_epi32(z, 1)],

                        av1_x_by_xplus1[_mm_extract_epi32(z, 0)]);

      xx_storeu_128(A + i * buf_stride + j, a_res);

      const __m128i a_complement =

          _mm_sub_epi32(_mm_set1_epi32(SGRPROJ_SGR), a_res);

      // sum1 might have lanes greater than 2^15, so we can't use madd to do

      // multiplication involving sum1. However, a_complement and one_over_n

      // are both less than 256, so we can multiply them first.

      const __m128i a_comp_over_n = _mm_madd_epi16(a_complement, one_over_n);

      const __m128i b_int = _mm_mullo_epi32(a_comp_over_n, sum1);

      const __m128i b_res =

          _mm_srli_epi32(_mm_add_epi32(b_int, rnd_res), SGRPROJ_RECIP_BITS);

      xx_storeu_128(B + i * buf_stride + j, b_res);

    }

  }

}

// Calculate 4 values of the "cross sum" starting at buf. This is a 3x3 filter

// where the outer four corners have weight 3 and all other pixels have weight

// 4.

//

// Pixels are indexed like this:

// xtl  xt   xtr

// xl    x   xr

// xbl  xb   xbr

//

// buf points to x

//

// fours = xl + xt + xr + xb + x

// threes = xtl + xtr + xbr + xbl

// cross_sum = 4 * fours + 3 * threes

//           = 4 * (fours + threes) - threes

//           = (fours + threes) << 2 - threes

static inline __m128i cross_sum(const int32_t *buf, int stride) {

  const __m128i xtl = xx_loadu_128(buf - 1 - stride);

  const __m128i xt = xx_loadu_128(buf - stride);

  const __m128i xtr = xx_loadu_128(buf + 1 - stride);

  const __m128i xl = xx_loadu_128(buf - 1);

  const __m128i x = xx_loadu_128(buf);

  const __m128i xr = xx_loadu_128(buf + 1);

  const __m128i xbl = xx_loadu_128(buf - 1 + stride);

  const __m128i xb = xx_loadu_128(buf + stride);

  const __m128i xbr = xx_loadu_128(buf + 1 + stride);

  const __m128i fours = _mm_add_epi32(

      xl, _mm_add_epi32(xt, _mm_add_epi32(xr, _mm_add_epi32(xb, x))));

  const __m128i threes =

      _mm_add_epi32(xtl, _mm_add_epi32(xtr, _mm_add_epi32(xbr, xbl)));

  return _mm_sub_epi32(_mm_slli_epi32(_mm_add_epi32(fours, threes), 2), threes);

}

// The final filter for self-guided restoration. Computes a weighted average

// across A, B with "cross sums" (see cross_sum implementation above).

static void final_filter(int32_t *dst, int dst_stride, const int32_t *A,

                         const int32_t *B, int buf_stride, const void *dgd8,

                         int dgd_stride, int width, int height, int highbd) {

  const int nb = 5;

  const __m128i rounding =

      round_for_shift(SGRPROJ_SGR_BITS + nb - SGRPROJ_RST_BITS);

  const uint8_t *dgd_real =

      highbd ? (const uint8_t *)CONVERT_TO_SHORTPTR(dgd8) : dgd8;

  for (int i = 0; i < height; ++i) {

    for (int j = 0; j < width; j += 4) {

      const __m128i a = cross_sum(A + i * buf_stride + j, buf_stride);

      const __m128i b = cross_sum(B + i * buf_stride + j, buf_stride);

      const __m128i raw =

          xx_loadl_64(dgd_real + ((i * dgd_stride + j) << highbd));

      const __m128i src =

          highbd ? _mm_cvtepu16_epi32(raw) : _mm_cvtepu8_epi32(raw);

      __m128i v = _mm_add_epi32(_mm_madd_epi16(a, src), b);

      __m128i w = _mm_srai_epi32(_mm_add_epi32(v, rounding),

                                 SGRPROJ_SGR_BITS + nb - SGRPROJ_RST_BITS);

      xx_storeu_128(dst + i * dst_stride + j, w);

    }

  }

}

// Assumes that C, D are integral images for the original buffer which has been

// extended to have a padding of SGRPROJ_BORDER_VERT/SGRPROJ_BORDER_HORZ pixels

// on the sides. A, B, C, D point at logical position (0, 0).

static void calc_ab_fast(int32_t *A, int32_t *B, const int32_t *C,

                         const int32_t *D, int width, int height,

                         int buf_stride, int bit_depth, int sgr_params_idx,

                         int radius_idx) {

  const sgr_params_type *const params = &av1_sgr_params[sgr_params_idx];

  const int r = params->r[radius_idx];

  const int n = (2 * r + 1) * (2 * r + 1);

  const __m128i s = _mm_set1_epi32(params->s[radius_idx]);

  // one_over_n[n-1] is 2^12/n, so easily fits in an int16

  const __m128i one_over_n = _mm_set1_epi32(av1_one_by_x[n - 1]);

  const __m128i rnd_z = round_for_shift(SGRPROJ_MTABLE_BITS);

  const __m128i rnd_res = round_for_shift(SGRPROJ_RECIP_BITS);

  // Set up masks

  const __m128i ones32 = _mm_set_epi32(0, 0, ~0, ~0);

  __m128i mask[4];

  for (int idx = 0; idx < 4; idx++) {

    const __m128i shift = _mm_cvtsi32_si128(8 * (4 - idx));

    mask[idx] = _mm_cvtepi8_epi32(_mm_srl_epi64(ones32, shift));

  }

  for (int i = -1; i < height + 1; i += 2) {

    for (int j = -1; j < width + 1; j += 4) {

      const int32_t *Cij = C + i * buf_stride + j;

      const int32_t *Dij = D + i * buf_stride + j;

      __m128i sum1 = boxsum_from_ii(Dij, buf_stride, r);

      __m128i sum2 = boxsum_from_ii(Cij, buf_stride, r);

      // When width + 2 isn't a multiple of 4, sum1 and sum2 will contain

      // some uninitialised data in their upper words. We use a mask to

      // ensure that these bits are set to 0.

      int idx = AOMMIN(4, width + 1 - j);

      assert(idx >= 1);

      if (idx < 4) {

        sum1 = _mm_and_si128(mask[idx], sum1);

        sum2 = _mm_and_si128(mask[idx], sum2);

      }

      const __m128i p = compute_p(sum1, sum2, bit_depth, n);

      const __m128i z = _mm_min_epi32(

          _mm_srli_epi32(_mm_add_epi32(_mm_mullo_epi32(p, s), rnd_z),

                         SGRPROJ_MTABLE_BITS),

          _mm_set1_epi32(255));

      // 'Gather' type instructions are not available pre-AVX2, so synthesize a

      // gather using scalar loads.

      const __m128i a_res =

          _mm_set_epi32(av1_x_by_xplus1[_mm_extract_epi32(z, 3)],

                        av1_x_by_xplus1[_mm_extract_epi32(z, 2)],

                        av1_x_by_xplus1[_mm_extract_epi32(z, 1)],

                        av1_x_by_xplus1[_mm_extract_epi32(z, 0)]);

      xx_storeu_128(A + i * buf_stride + j, a_res);

      const __m128i a_complement =

          _mm_sub_epi32(_mm_set1_epi32(SGRPROJ_SGR), a_res);

      // sum1 might have lanes greater than 2^15, so we can't use madd to do

      // multiplication involving sum1. However, a_complement and one_over_n

      // are both less than 256, so we can multiply them first.

      const __m128i a_comp_over_n = _mm_madd_epi16(a_complement, one_over_n);

      const __m128i b_int = _mm_mullo_epi32(a_comp_over_n, sum1);

      const __m128i b_res =

          _mm_srli_epi32(_mm_add_epi32(b_int, rnd_res), SGRPROJ_RECIP_BITS);

      xx_storeu_128(B + i * buf_stride + j, b_res);

    }

  }

}

// Calculate 4 values of the "cross sum" starting at buf.

//

// Pixels are indexed like this:

// xtl  xt   xtr

//  -   buf   -

// xbl  xb   xbr

//

// Pixels are weighted like this:

//  5    6    5

//  0    0    0

//  5    6    5

//

// fives = xtl + xtr + xbl + xbr

// sixes = xt + xb

// cross_sum = 6 * sixes + 5 * fives

//           = 5 * (fives + sixes) - sixes

//           = (fives + sixes) << 2 + (fives + sixes) + sixes

static inline __m128i cross_sum_fast_even_row(const int32_t *buf, int stride) {

  const __m128i xtl = xx_loadu_128(buf - 1 - stride);

  const __m128i xt = xx_loadu_128(buf - stride);

  const __m128i xtr = xx_loadu_128(buf + 1 - stride);

  const __m128i xbl = xx_loadu_128(buf - 1 + stride);

  const __m128i xb = xx_loadu_128(buf + stride);

  const __m128i xbr = xx_loadu_128(buf + 1 + stride);

  const __m128i fives =

      _mm_add_epi32(xtl, _mm_add_epi32(xtr, _mm_add_epi32(xbr, xbl)));

  const __m128i sixes = _mm_add_epi32(xt, xb);

  const __m128i fives_plus_sixes = _mm_add_epi32(fives, sixes);

  return _mm_add_epi32(

      _mm_add_epi32(_mm_slli_epi32(fives_plus_sixes, 2), fives_plus_sixes),

      sixes);

}

// Calculate 4 values of the "cross sum" starting at buf.

//

// Pixels are indexed like this:

// xl    x   xr

//

// Pixels are weighted like this:

//  5    6    5

//

// buf points to x

//

// fives = xl + xr

// sixes = x

// cross_sum = 5 * fives + 6 * sixes

//           = 4 * (fives + sixes) + (fives + sixes) + sixes

//           = (fives + sixes) << 2 + (fives + sixes) + sixes

static inline __m128i cross_sum_fast_odd_row(const int32_t *buf) {

  const __m128i xl = xx_loadu_128(buf - 1);

  const __m128i x = xx_loadu_128(buf);

  const __m128i xr = xx_loadu_128(buf + 1);

  const __m128i fives = _mm_add_epi32(xl, xr);

  const __m128i sixes = x;

  const __m128i fives_plus_sixes = _mm_add_epi32(fives, sixes);

  return _mm_add_epi32(

      _mm_add_epi32(_mm_slli_epi32(fives_plus_sixes, 2), fives_plus_sixes),

      sixes);

}

// The final filter for the self-guided restoration. Computes a

// weighted average across A, B with "cross sums" (see cross_sum_...

// implementations above).

static void final_filter_fast(int32_t *dst, int dst_stride, const int32_t *A,

                              const int32_t *B, int buf_stride,

                              const void *dgd8, int dgd_stride, int width,

                              int height, int highbd) {

  const int nb0 = 5;

  const int nb1 = 4;

  const __m128i rounding0 =

      round_for_shift(SGRPROJ_SGR_BITS + nb0 - SGRPROJ_RST_BITS);

  const __m128i rounding1 =

      round_for_shift(SGRPROJ_SGR_BITS + nb1 - SGRPROJ_RST_BITS);

  const uint8_t *dgd_real =

      highbd ? (const uint8_t *)CONVERT_TO_SHORTPTR(dgd8) : dgd8;

  for (int i = 0; i < height; ++i) {

    if (!(i & 1)) {  // even row

      for (int j = 0; j < width; j += 4) {

        const __m128i a =

            cross_sum_fast_even_row(A + i * buf_stride + j, buf_stride);

        const __m128i b =

            cross_sum_fast_even_row(B + i * buf_stride + j, buf_stride);

        const __m128i raw =

            xx_loadl_64(dgd_real + ((i * dgd_stride + j) << highbd));

        const __m128i src =

            highbd ? _mm_cvtepu16_epi32(raw) : _mm_cvtepu8_epi32(raw);

        __m128i v = _mm_add_epi32(_mm_madd_epi16(a, src), b);

        __m128i w = _mm_srai_epi32(_mm_add_epi32(v, rounding0),

                                   SGRPROJ_SGR_BITS + nb0 - SGRPROJ_RST_BITS);

        xx_storeu_128(dst + i * dst_stride + j, w);

      }

    } else {  // odd row

      for (int j = 0; j < width; j += 4) {

        const __m128i a = cross_sum_fast_odd_row(A + i * buf_stride + j);

        const __m128i b = cross_sum_fast_odd_row(B + i * buf_stride + j);

        const __m128i raw =

            xx_loadl_64(dgd_real + ((i * dgd_stride + j) << highbd));

        const __m128i src =

            highbd ? _mm_cvtepu16_epi32(raw) : _mm_cvtepu8_epi32(raw);

        __m128i v = _mm_add_epi32(_mm_madd_epi16(a, src), b);

        __m128i w = _mm_srai_epi32(_mm_add_epi32(v, rounding1),

                                   SGRPROJ_SGR_BITS + nb1 - SGRPROJ_RST_BITS);

        xx_storeu_128(dst + i * dst_stride + j, w);

      }

    }

  }

}

int av1_selfguided_restoration_sse4_1(const uint8_t *dgd8, int width,

                                      int height, int dgd_stride, int32_t *flt0,

                                      int32_t *flt1, int flt_stride,

                                      int sgr_params_idx, int bit_depth,

                                      int highbd) {

  int32_t *buf = (int32_t *)aom_memalign(

      16, 4 * sizeof(*buf) * RESTORATION_PROC_UNIT_PELS);

  if (!buf) return -1;

  memset(buf, 0, 4 * sizeof(*buf) * RESTORATION_PROC_UNIT_PELS);

  const int width_ext = width + 2 * SGRPROJ_BORDER_HORZ;

  const int height_ext = height + 2 * SGRPROJ_BORDER_VERT;

  // Adjusting the stride of A and B here appears to avoid bad cache effects,

  // leading to a significant speed improvement.

  // We also align the stride to a multiple of 16 bytes for efficiency.

  int buf_stride = ((width_ext + 3) & ~3) + 16;

  // The "tl" pointers point at the top-left of the initialised data for the

  // array. Adding 3 here ensures that column 1 is 16-byte aligned.

  int32_t *Atl = buf + 0 * RESTORATION_PROC_UNIT_PELS + 3;

  int32_t *Btl = buf + 1 * RESTORATION_PROC_UNIT_PELS + 3;

  int32_t *Ctl = buf + 2 * RESTORATION_PROC_UNIT_PELS + 3;

  int32_t *Dtl = buf + 3 * RESTORATION_PROC_UNIT_PELS + 3;

  // The "0" pointers are (- SGRPROJ_BORDER_VERT, -SGRPROJ_BORDER_HORZ). Note

  // there's a zero row and column in A, B (integral images), so we move down

  // and right one for them.

  const int buf_diag_border =

      SGRPROJ_BORDER_HORZ + buf_stride * SGRPROJ_BORDER_VERT;

  int32_t *A0 = Atl + 1 + buf_stride;

  int32_t *B0 = Btl + 1 + buf_stride;

  int32_t *C0 = Ctl + 1 + buf_stride;

  int32_t *D0 = Dtl + 1 + buf_stride;

  // Finally, A, B, C, D point at position (0, 0).

  int32_t *A = A0 + buf_diag_border;

  int32_t *B = B0 + buf_diag_border;

  int32_t *C = C0 + buf_diag_border;

  int32_t *D = D0 + buf_diag_border;

  const int dgd_diag_border =

      SGRPROJ_BORDER_HORZ + dgd_stride * SGRPROJ_BORDER_VERT;

  const uint8_t *dgd0 = dgd8 - dgd_diag_border;

  // Generate integral images from the input. C will contain sums of squares; D

  // will contain just sums

  if (highbd)

    integral_images_highbd(CONVERT_TO_SHORTPTR(dgd0), dgd_stride, width_ext,

                           height_ext, Ctl, Dtl, buf_stride);

  else

    integral_images(dgd0, dgd_stride, width_ext, height_ext, Ctl, Dtl,

                    buf_stride);

  const sgr_params_type *const params = &av1_sgr_params[sgr_params_idx];

  // Write to flt0 and flt1

  // If params->r == 0 we skip the corresponding filter. We only allow one of

  // the radii to be 0, as having both equal to 0 would be equivalent to

  // skipping SGR entirely.

  assert(!(params->r[0] == 0 && params->r[1] == 0));

  assert(params->r[0] < AOMMIN(SGRPROJ_BORDER_VERT, SGRPROJ_BORDER_HORZ));

  assert(params->r[1] < AOMMIN(SGRPROJ_BORDER_VERT, SGRPROJ_BORDER_HORZ));

  if (params->r[0] > 0) {

    calc_ab_fast(A, B, C, D, width, height, buf_stride, bit_depth,

                 sgr_params_idx, 0);

    final_filter_fast(flt0, flt_stride, A, B, buf_stride, dgd8, dgd_stride,

                      width, height, highbd);

  }

  if (params->r[1] > 0) {

    calc_ab(A, B, C, D, width, height, buf_stride, bit_depth, sgr_params_idx,

            1);

    final_filter(flt1, flt_stride, A, B, buf_stride, dgd8, dgd_stride, width,

                 height, highbd);

  }

  aom_free(buf);

  return 0;

}

int av1_apply_selfguided_restoration_sse4_1(const uint8_t *dat8, int width,

                                            int height, int stride, int eps,

                                            const int *xqd, uint8_t *dst8,

                                            int dst_stride, int32_t *tmpbuf,

                                            int bit_depth, int highbd) {

  int32_t *flt0 = tmpbuf;

  int32_t *flt1 = flt0 + RESTORATION_UNITPELS_MAX;

  assert(width * height <= RESTORATION_UNITPELS_MAX);

  const int ret = av1_selfguided_restoration_sse4_1(

      dat8, width, height, stride, flt0, flt1, width, eps, bit_depth, highbd);

  if (ret != 0) return ret;

  const sgr_params_type *const params = &av1_sgr_params[eps];

  int xq[2];

  av1_decode_xq(xqd, xq, params);

  __m128i xq0 = _mm_set1_epi32(xq[0]);

  __m128i xq1 = _mm_set1_epi32(xq[1]);

  for (int i = 0; i < height; ++i) {

    // Calculate output in batches of 8 pixels

    for (int j = 0; j < width; j += 8) {

      const int k = i * width + j;

      const int m = i * dst_stride + j;

      const uint8_t *dat8ij = dat8 + i * stride + j;

      __m128i src;

      if (highbd) {

        src = xx_loadu_128(CONVERT_TO_SHORTPTR(dat8ij));

      } else {

        src = _mm_cvtepu8_epi16(xx_loadl_64(dat8ij));

      }

      const __m128i u = _mm_slli_epi16(src, SGRPROJ_RST_BITS);

      const __m128i u_0 = _mm_cvtepu16_epi32(u);

      const __m128i u_1 = _mm_cvtepu16_epi32(_mm_srli_si128(u, 8));

      __m128i v_0 = _mm_slli_epi32(u_0, SGRPROJ_PRJ_BITS);

      __m128i v_1 = _mm_slli_epi32(u_1, SGRPROJ_PRJ_BITS);

      if (params->r[0] > 0) {

        const __m128i f1_0 = _mm_sub_epi32(xx_loadu_128(&flt0[k]), u_0);

        v_0 = _mm_add_epi32(v_0, _mm_mullo_epi32(xq0, f1_0));

        const __m128i f1_1 = _mm_sub_epi32(xx_loadu_128(&flt0[k + 4]), u_1);

        v_1 = _mm_add_epi32(v_1, _mm_mullo_epi32(xq0, f1_1));

      }

      if (params->r[1] > 0) {

        const __m128i f2_0 = _mm_sub_epi32(xx_loadu_128(&flt1[k]), u_0);

        v_0 = _mm_add_epi32(v_0, _mm_mullo_epi32(xq1, f2_0));

        const __m128i f2_1 = _mm_sub_epi32(xx_loadu_128(&flt1[k + 4]), u_1);

        v_1 = _mm_add_epi32(v_1, _mm_mullo_epi32(xq1, f2_1));

      }

      const __m128i rounding =

          round_for_shift(SGRPROJ_PRJ_BITS + SGRPROJ_RST_BITS);

      const __m128i w_0 = _mm_srai_epi32(_mm_add_epi32(v_0, rounding),

                                         SGRPROJ_PRJ_BITS + SGRPROJ_RST_BITS);

      const __m128i w_1 = _mm_srai_epi32(_mm_add_epi32(v_1, rounding),

                                         SGRPROJ_PRJ_BITS + SGRPROJ_RST_BITS);

      if (highbd) {

        // Pack into 16 bits and clamp to [0, 2^bit_depth)

        const __m128i tmp = _mm_packus_epi32(w_0, w_1);

        const __m128i max = _mm_set1_epi16((1 << bit_depth) - 1);

        const __m128i res = _mm_min_epi16(tmp, max);

        xx_storeu_128(CONVERT_TO_SHORTPTR(dst8 + m), res);

      } else {

        // Pack into 8 bits and clamp to [0, 256)

        const __m128i tmp = _mm_packs_epi32(w_0, w_1);

        const __m128i res = _mm_packus_epi16(tmp, tmp /* "don't care" value */);

        xx_storel_64(dst8 + m, res);

      }

    }

  }

  return 0;

}