/*

 * 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 "aom_dsp/aom_simd.h"

#define SIMD_FUNC(name) name##_avx2

#include "av1/common/cdef_block_simd.h"

// Mask used to shuffle the elements present in 256bit register.

const int shuffle_reg_256bit[8] = { 0x0b0a0d0c, 0x07060908, 0x03020504,

                                    0x0f0e0100, 0x0b0a0d0c, 0x07060908,

                                    0x03020504, 0x0f0e0100 };

/* partial A is a 16-bit vector of the form:

[x8 - - x1 | x16 - - x9] and partial B has the form:

[0  y1 - y7 | 0 y9 - y15].

This function computes (x1^2+y1^2)*C1 + (x2^2+y2^2)*C2 + ...

(x7^2+y2^7)*C7 + (x8^2+0^2)*C8 on each 128-bit lane. Here the C1..C8 constants

are in const1 and const2. */

static INLINE __m256i fold_mul_and_sum_avx2(__m256i *partiala,

                                            __m256i *partialb,

                                            const __m256i *const1,

                                            const __m256i *const2) {

  __m256i tmp;

  /* Reverse partial B. */

  *partialb = _mm256_shuffle_epi8(

      *partialb, _mm256_loadu_si256((const __m256i *)shuffle_reg_256bit));

  /* Interleave the x and y values of identical indices and pair x8 with 0. */

  tmp = *partiala;

  *partiala = _mm256_unpacklo_epi16(*partiala, *partialb);

  *partialb = _mm256_unpackhi_epi16(tmp, *partialb);

  /* Square and add the corresponding x and y values. */

  *partiala = _mm256_madd_epi16(*partiala, *partiala);

  *partialb = _mm256_madd_epi16(*partialb, *partialb);

  /* Multiply by constant. */

  *partiala = _mm256_mullo_epi32(*partiala, *const1);

  *partialb = _mm256_mullo_epi32(*partialb, *const2);

  /* Sum all results. */

  *partiala = _mm256_add_epi32(*partiala, *partialb);

  return *partiala;

}

static INLINE __m256i hsum4_avx2(__m256i *x0, __m256i *x1, __m256i *x2,

                                 __m256i *x3) {

  const __m256i t0 = _mm256_unpacklo_epi32(*x0, *x1);

  const __m256i t1 = _mm256_unpacklo_epi32(*x2, *x3);

  const __m256i t2 = _mm256_unpackhi_epi32(*x0, *x1);

  const __m256i t3 = _mm256_unpackhi_epi32(*x2, *x3);

  *x0 = _mm256_unpacklo_epi64(t0, t1);

  *x1 = _mm256_unpackhi_epi64(t0, t1);

  *x2 = _mm256_unpacklo_epi64(t2, t3);

  *x3 = _mm256_unpackhi_epi64(t2, t3);

  return _mm256_add_epi32(_mm256_add_epi32(*x0, *x1),

                          _mm256_add_epi32(*x2, *x3));

}

/* Computes cost for directions 0, 5, 6 and 7. We can call this function again

to compute the remaining directions. */

static INLINE __m256i compute_directions_avx2(__m256i *lines,

                                              int32_t cost_frist_8x8[4],

                                              int32_t cost_second_8x8[4]) {

  __m256i partial4a, partial4b, partial5a, partial5b, partial7a, partial7b;

  __m256i partial6;

  __m256i tmp;

  /* Partial sums for lines 0 and 1. */

  partial4a = _mm256_slli_si256(lines[0], 14);

  partial4b = _mm256_srli_si256(lines[0], 2);

  partial4a = _mm256_add_epi16(partial4a, _mm256_slli_si256(lines[1], 12));

  partial4b = _mm256_add_epi16(partial4b, _mm256_srli_si256(lines[1], 4));

  tmp = _mm256_add_epi16(lines[0], lines[1]);

  partial5a = _mm256_slli_si256(tmp, 10);

  partial5b = _mm256_srli_si256(tmp, 6);

  partial7a = _mm256_slli_si256(tmp, 4);

  partial7b = _mm256_srli_si256(tmp, 12);

  partial6 = tmp;

  /* Partial sums for lines 2 and 3. */

  partial4a = _mm256_add_epi16(partial4a, _mm256_slli_si256(lines[2], 10));

  partial4b = _mm256_add_epi16(partial4b, _mm256_srli_si256(lines[2], 6));

  partial4a = _mm256_add_epi16(partial4a, _mm256_slli_si256(lines[3], 8));

  partial4b = _mm256_add_epi16(partial4b, _mm256_srli_si256(lines[3], 8));

  tmp = _mm256_add_epi16(lines[2], lines[3]);

  partial5a = _mm256_add_epi16(partial5a, _mm256_slli_si256(tmp, 8));

  partial5b = _mm256_add_epi16(partial5b, _mm256_srli_si256(tmp, 8));

  partial7a = _mm256_add_epi16(partial7a, _mm256_slli_si256(tmp, 6));

  partial7b = _mm256_add_epi16(partial7b, _mm256_srli_si256(tmp, 10));

  partial6 = _mm256_add_epi16(partial6, tmp);

  /* Partial sums for lines 4 and 5. */

  partial4a = _mm256_add_epi16(partial4a, _mm256_slli_si256(lines[4], 6));

  partial4b = _mm256_add_epi16(partial4b, _mm256_srli_si256(lines[4], 10));

  partial4a = _mm256_add_epi16(partial4a, _mm256_slli_si256(lines[5], 4));

  partial4b = _mm256_add_epi16(partial4b, _mm256_srli_si256(lines[5], 12));

  tmp = _mm256_add_epi16(lines[4], lines[5]);

  partial5a = _mm256_add_epi16(partial5a, _mm256_slli_si256(tmp, 6));

  partial5b = _mm256_add_epi16(partial5b, _mm256_srli_si256(tmp, 10));

  partial7a = _mm256_add_epi16(partial7a, _mm256_slli_si256(tmp, 8));

  partial7b = _mm256_add_epi16(partial7b, _mm256_srli_si256(tmp, 8));

  partial6 = _mm256_add_epi16(partial6, tmp);

  /* Partial sums for lines 6 and 7. */

  partial4a = _mm256_add_epi16(partial4a, _mm256_slli_si256(lines[6], 2));

  partial4b = _mm256_add_epi16(partial4b, _mm256_srli_si256(lines[6], 14));

  partial4a = _mm256_add_epi16(partial4a, lines[7]);

  tmp = _mm256_add_epi16(lines[6], lines[7]);

  partial5a = _mm256_add_epi16(partial5a, _mm256_slli_si256(tmp, 4));

  partial5b = _mm256_add_epi16(partial5b, _mm256_srli_si256(tmp, 12));

  partial7a = _mm256_add_epi16(partial7a, _mm256_slli_si256(tmp, 10));

  partial7b = _mm256_add_epi16(partial7b, _mm256_srli_si256(tmp, 6));

  partial6 = _mm256_add_epi16(partial6, tmp);

  const __m256i const_reg_1 =

      _mm256_set_epi32(210, 280, 420, 840, 210, 280, 420, 840);

  const __m256i const_reg_2 =

      _mm256_set_epi32(105, 120, 140, 168, 105, 120, 140, 168);

  const __m256i const_reg_3 = _mm256_set_epi32(210, 420, 0, 0, 210, 420, 0, 0);

  const __m256i const_reg_4 =

      _mm256_set_epi32(105, 105, 105, 140, 105, 105, 105, 140);

  /* Compute costs in terms of partial sums. */

  partial4a =

      fold_mul_and_sum_avx2(&partial4a, &partial4b, &const_reg_1, &const_reg_2);

  partial7a =

      fold_mul_and_sum_avx2(&partial7a, &partial7b, &const_reg_3, &const_reg_4);

  partial5a =

      fold_mul_and_sum_avx2(&partial5a, &partial5b, &const_reg_3, &const_reg_4);

  partial6 = _mm256_madd_epi16(partial6, partial6);

  partial6 = _mm256_mullo_epi32(partial6, _mm256_set1_epi32(105));

  partial4a = hsum4_avx2(&partial4a, &partial5a, &partial6, &partial7a);

  _mm_storeu_si128((__m128i *)cost_frist_8x8,

                   _mm256_castsi256_si128(partial4a));

  _mm_storeu_si128((__m128i *)cost_second_8x8,

                   _mm256_extractf128_si256(partial4a, 1));

  return partial4a;

}

/* transpose and reverse the order of the lines -- equivalent to a 90-degree

counter-clockwise rotation of the pixels. */

static INLINE void array_reverse_transpose_8x8_avx2(__m256i *in, __m256i *res) {

  const __m256i tr0_0 = _mm256_unpacklo_epi16(in[0], in[1]);

  const __m256i tr0_1 = _mm256_unpacklo_epi16(in[2], in[3]);

  const __m256i tr0_2 = _mm256_unpackhi_epi16(in[0], in[1]);

  const __m256i tr0_3 = _mm256_unpackhi_epi16(in[2], in[3]);

  const __m256i tr0_4 = _mm256_unpacklo_epi16(in[4], in[5]);

  const __m256i tr0_5 = _mm256_unpacklo_epi16(in[6], in[7]);

  const __m256i tr0_6 = _mm256_unpackhi_epi16(in[4], in[5]);

  const __m256i tr0_7 = _mm256_unpackhi_epi16(in[6], in[7]);

  const __m256i tr1_0 = _mm256_unpacklo_epi32(tr0_0, tr0_1);

  const __m256i tr1_1 = _mm256_unpacklo_epi32(tr0_4, tr0_5);

  const __m256i tr1_2 = _mm256_unpackhi_epi32(tr0_0, tr0_1);

  const __m256i tr1_3 = _mm256_unpackhi_epi32(tr0_4, tr0_5);

  const __m256i tr1_4 = _mm256_unpacklo_epi32(tr0_2, tr0_3);

  const __m256i tr1_5 = _mm256_unpacklo_epi32(tr0_6, tr0_7);

  const __m256i tr1_6 = _mm256_unpackhi_epi32(tr0_2, tr0_3);

  const __m256i tr1_7 = _mm256_unpackhi_epi32(tr0_6, tr0_7);

  res[7] = _mm256_unpacklo_epi64(tr1_0, tr1_1);

  res[6] = _mm256_unpackhi_epi64(tr1_0, tr1_1);

  res[5] = _mm256_unpacklo_epi64(tr1_2, tr1_3);

  res[4] = _mm256_unpackhi_epi64(tr1_2, tr1_3);

  res[3] = _mm256_unpacklo_epi64(tr1_4, tr1_5);

  res[2] = _mm256_unpackhi_epi64(tr1_4, tr1_5);

  res[1] = _mm256_unpacklo_epi64(tr1_6, tr1_7);

  res[0] = _mm256_unpackhi_epi64(tr1_6, tr1_7);

}

void cdef_find_dir_dual_avx2(const uint16_t *img1, const uint16_t *img2,

                             int stride, int32_t *var_out_1st,

                             int32_t *var_out_2nd, int coeff_shift,

                             int *out_dir_1st_8x8, int *out_dir_2nd_8x8) {

  int32_t cost_first_8x8[8];

  int32_t cost_second_8x8[8];

  // Used to store the best cost for 2 8x8's.

  int32_t best_cost[2] = { 0 };

  // Best direction for 2 8x8's.

  int best_dir[2] = { 0 };

  const __m128i const_coeff_shift_reg = _mm_cvtsi32_si128(coeff_shift);

  const __m256i const_128_reg = _mm256_set1_epi16(128);

  __m256i lines[8];

  for (int i = 0; i < 8; i++) {

    const __m128i src_1 = _mm_loadu_si128((const __m128i *)&img1[i * stride]);

    const __m128i src_2 = _mm_loadu_si128((const __m128i *)&img2[i * stride]);

    lines[i] = _mm256_insertf128_si256(_mm256_castsi128_si256(src_1), src_2, 1);

    lines[i] = _mm256_sub_epi16(

        _mm256_sra_epi16(lines[i], const_coeff_shift_reg), const_128_reg);

  }

  /* Compute "mostly vertical" directions. */

  const __m256i dir47 =

      compute_directions_avx2(lines, cost_first_8x8 + 4, cost_second_8x8 + 4);

  /* Transpose and reverse the order of the lines. */

  array_reverse_transpose_8x8_avx2(lines, lines);

  /* Compute "mostly horizontal" directions. */

  const __m256i dir03 =

      compute_directions_avx2(lines, cost_first_8x8, cost_second_8x8);

  __m256i max = _mm256_max_epi32(dir03, dir47);

  max =

      _mm256_max_epi32(max, _mm256_or_si256(_mm256_srli_si256(max, 8),

                                            _mm256_slli_si256(max, 16 - (8))));

  max =

      _mm256_max_epi32(max, _mm256_or_si256(_mm256_srli_si256(max, 4),

                                            _mm256_slli_si256(max, 16 - (4))));

  const __m128i first_8x8_output = _mm256_castsi256_si128(max);

  const __m128i second_8x8_output = _mm256_extractf128_si256(max, 1);

  const __m128i cmpeg_res_00 =

      _mm_cmpeq_epi32(first_8x8_output, _mm256_castsi256_si128(dir47));

  const __m128i cmpeg_res_01 =

      _mm_cmpeq_epi32(first_8x8_output, _mm256_castsi256_si128(dir03));

  const __m128i cmpeg_res_10 =

      _mm_cmpeq_epi32(second_8x8_output, _mm256_extractf128_si256(dir47, 1));

  const __m128i cmpeg_res_11 =

      _mm_cmpeq_epi32(second_8x8_output, _mm256_extractf128_si256(dir03, 1));

  const __m128i t_first_8x8 = _mm_packs_epi32(cmpeg_res_01, cmpeg_res_00);

  const __m128i t_second_8x8 = _mm_packs_epi32(cmpeg_res_11, cmpeg_res_10);

  best_cost[0] = _mm_cvtsi128_si32(_mm256_castsi256_si128(max));

  best_cost[1] = _mm_cvtsi128_si32(second_8x8_output);

  best_dir[0] = _mm_movemask_epi8(_mm_packs_epi16(t_first_8x8, t_first_8x8));

  best_dir[0] =

      get_msb(best_dir[0] ^ (best_dir[0] - 1));  // Count trailing zeros

  best_dir[1] = _mm_movemask_epi8(_mm_packs_epi16(t_second_8x8, t_second_8x8));

  best_dir[1] =

      get_msb(best_dir[1] ^ (best_dir[1] - 1));  // Count trailing zeros

  /* Difference between the optimal variance and the variance along the

     orthogonal direction. Again, the sum(x^2) terms cancel out. */

  *var_out_1st = best_cost[0] - cost_first_8x8[(best_dir[0] + 4) & 7];

  *var_out_2nd = best_cost[1] - cost_second_8x8[(best_dir[1] + 4) & 7];

  /* We'd normally divide by 840, but dividing by 1024 is close enough

  for what we're going to do with this. */

  *var_out_1st >>= 10;

  *var_out_2nd >>= 10;

  *out_dir_1st_8x8 = best_dir[0];

  *out_dir_2nd_8x8 = best_dir[1];

}

void cdef_copy_rect8_8bit_to_16bit_avx2(uint16_t *dst, int dstride,

                                        const uint8_t *src, int sstride,

                                        int width, int height) {

  int j = 0;

  int remaining_width = width;

  assert(height % 2 == 0);

  assert(height > 0);

  assert(width > 0);

  // Process multiple 32 pixels at a time.

  if (remaining_width > 31) {

    int i = 0;

    do {

      j = 0;

      do {

        __m128i row00 =

            _mm_loadu_si128((const __m128i *)&src[(i + 0) * sstride + (j + 0)]);

        __m128i row01 = _mm_loadu_si128(

            (const __m128i *)&src[(i + 0) * sstride + (j + 16)]);

        __m128i row10 =

            _mm_loadu_si128((const __m128i *)&src[(i + 1) * sstride + (j + 0)]);

        __m128i row11 = _mm_loadu_si128(

            (const __m128i *)&src[(i + 1) * sstride + (j + 16)]);

        _mm256_storeu_si256((__m256i *)&dst[(i + 0) * dstride + (j + 0)],

                            _mm256_cvtepu8_epi16(row00));

        _mm256_storeu_si256((__m256i *)&dst[(i + 0) * dstride + (j + 16)],

                            _mm256_cvtepu8_epi16(row01));

        _mm256_storeu_si256((__m256i *)&dst[(i + 1) * dstride + (j + 0)],

                            _mm256_cvtepu8_epi16(row10));

        _mm256_storeu_si256((__m256i *)&dst[(i + 1) * dstride + (j + 16)],

                            _mm256_cvtepu8_epi16(row11));

        j += 32;

      } while (j <= width - 32);

      i += 2;

    } while (i < height);

    remaining_width = width & 31;

  }

  // Process 16 pixels at a time.

  if (remaining_width > 15) {

    int i = 0;

    do {

      __m128i row0 =

          _mm_loadu_si128((const __m128i *)&src[(i + 0) * sstride + j]);

      __m128i row1 =

          _mm_loadu_si128((const __m128i *)&src[(i + 1) * sstride + j]);

      _mm256_storeu_si256((__m256i *)&dst[(i + 0) * dstride + j],

                          _mm256_cvtepu8_epi16(row0));

      _mm256_storeu_si256((__m256i *)&dst[(i + 1) * dstride + j],

                          _mm256_cvtepu8_epi16(row1));

      i += 2;

    } while (i < height);

    remaining_width = width & 15;

    j += 16;

  }

  // Process 8 pixels at a time.

  if (remaining_width > 7) {

    int i = 0;

    do {

      __m128i row0 =

          _mm_loadl_epi64((const __m128i *)&src[(i + 0) * sstride + j]);

      __m128i row1 =

          _mm_loadl_epi64((const __m128i *)&src[(i + 1) * sstride + j]);

      _mm_storeu_si128((__m128i *)&dst[(i + 0) * dstride + j],

                       _mm_unpacklo_epi8(row0, _mm_setzero_si128()));

      _mm_storeu_si128((__m128i *)&dst[(i + 1) * dstride + j],

                       _mm_unpacklo_epi8(row1, _mm_setzero_si128()));

      i += 2;

    } while (i < height);

    remaining_width = width & 7;

    j += 8;

  }

  // Process 4 pixels at a time.

  if (remaining_width > 3) {

    int i = 0;

    do {

      __m128i row0 =

          _mm_cvtsi32_si128(*((const int32_t *)&src[(i + 0) * sstride + j]));

      __m128i row1 =

          _mm_cvtsi32_si128(*((const int32_t *)&src[(i + 1) * sstride + j]));

      _mm_storel_epi64((__m128i *)&dst[(i + 0) * dstride + j],

                       _mm_unpacklo_epi8(row0, _mm_setzero_si128()));

      _mm_storel_epi64((__m128i *)&dst[(i + 1) * dstride + j],

                       _mm_unpacklo_epi8(row1, _mm_setzero_si128()));

      i += 2;

    } while (i < height);

    remaining_width = width & 3;

    j += 4;

  }

  // Process the remaining pixels.

  if (remaining_width) {

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

      for (int k = j; k < width; k++) {

        dst[i * dstride + k] = src[i * sstride + k];

      }

    }

  }

}