/*
 * Copyright (c) 2017, 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 <assert.h>
#include <emmintrin.h>  // SSE2

#include "aom/aom_integer.h"
#include "aom_dsp/x86/mem_sse2.h"
#include "av1/common/av1_common_int.h"
#include "av1/common/txb_common.h"

static inline void load_levels_4x4x5_sse2(const uint8_t *const src,
                                          const int stride,
                                          const ptrdiff_t *const offsets,
                                          __m128i *const level) {
  level[0] = load_8bit_4x4_to_1_reg_sse2(src + 1, stride);
  level[1] = load_8bit_4x4_to_1_reg_sse2(src + stride, stride);
  level[2] = load_8bit_4x4_to_1_reg_sse2(src + offsets[0], stride);
  level[3] = load_8bit_4x4_to_1_reg_sse2(src + offsets[1], stride);
  level[4] = load_8bit_4x4_to_1_reg_sse2(src + offsets[2], stride);
}

static inline void load_levels_8x2x5_sse2(const uint8_t *const src,
                                          const int stride,
                                          const ptrdiff_t *const offsets,
                                          __m128i *const level) {
  level[0] = load_8bit_8x2_to_1_reg_sse2(src + 1, stride);
  level[1] = load_8bit_8x2_to_1_reg_sse2(src + stride, stride);
  level[2] = load_8bit_8x2_to_1_reg_sse2(src + offsets[0], stride);
  level[3] = load_8bit_8x2_to_1_reg_sse2(src + offsets[1], stride);
  level[4] = load_8bit_8x2_to_1_reg_sse2(src + offsets[2], stride);
}

static inline void load_levels_16x1x5_sse2(const uint8_t *const src,
                                           const int stride,
                                           const ptrdiff_t *const offsets,
                                           __m128i *const level) {
  level[0] = _mm_loadu_si128((__m128i *)(src + 1));
  level[1] = _mm_loadu_si128((__m128i *)(src + stride));
  level[2] = _mm_loadu_si128((__m128i *)(src + offsets[0]));
  level[3] = _mm_loadu_si128((__m128i *)(src + offsets[1]));
  level[4] = _mm_loadu_si128((__m128i *)(src + offsets[2]));
}

static inline __m128i get_coeff_contexts_kernel_sse2(__m128i *const level) {
  const __m128i const_3 = _mm_set1_epi8(3);
  const __m128i const_4 = _mm_set1_epi8(4);
  __m128i count;

  count = _mm_min_epu8(level[0], const_3);
  level[1] = _mm_min_epu8(level[1], const_3);
  level[2] = _mm_min_epu8(level[2], const_3);
  level[3] = _mm_min_epu8(level[3], const_3);
  level[4] = _mm_min_epu8(level[4], const_3);
  count = _mm_add_epi8(count, level[1]);
  count = _mm_add_epi8(count, level[2]);
  count = _mm_add_epi8(count, level[3]);
  count = _mm_add_epi8(count, level[4]);
  count = _mm_avg_epu8(count, _mm_setzero_si128());
  count = _mm_min_epu8(count, const_4);
  return count;
}

static inline void get_4_nz_map_contexts_2d(const uint8_t *levels,
                                            const int width,
                                            const ptrdiff_t *const offsets,
                                            int8_t *const coeff_contexts) {
  const int stride = 4 + TX_PAD_HOR;
  const __m128i pos_to_offset_large = _mm_set1_epi8(21);
  __m128i pos_to_offset =
      (width == 4)
          ? _mm_setr_epi8(0, 1, 6, 6, 1, 6, 6, 21, 6, 6, 21, 21, 6, 21, 21, 21)
          : _mm_setr_epi8(0, 16, 16, 16, 16, 16, 16, 16, 6, 6, 21, 21, 6, 21,
                          21, 21);
  __m128i count;
  __m128i level[5];
  int8_t *cc = coeff_contexts;
  int col = width;

  assert(!(width % 4));

  do {
    load_levels_4x4x5_sse2(levels, stride, offsets, level);
    count = get_coeff_contexts_kernel_sse2(level);
    count = _mm_add_epi8(count, pos_to_offset);
    _mm_store_si128((__m128i *)cc, count);
    pos_to_offset = pos_to_offset_large;
    levels += 4 * stride;
    cc += 16;
    col -= 4;
  } while (col);

  coeff_contexts[0] = 0;
}

static inline void get_4_nz_map_contexts_ver(const uint8_t *levels,
                                             const int width,
                                             const ptrdiff_t *const offsets,
                                             int8_t *coeff_contexts) {
  const int stride = 4 + TX_PAD_HOR;
  const __m128i pos_to_offset =
      _mm_setr_epi8(SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 5,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 5,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 5,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 5,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10);
  __m128i count;
  __m128i level[5];
  int col = width;

  assert(!(width % 4));

  do {
    load_levels_4x4x5_sse2(levels, stride, offsets, level);
    count = get_coeff_contexts_kernel_sse2(level);
    count = _mm_add_epi8(count, pos_to_offset);
    _mm_store_si128((__m128i *)coeff_contexts, count);
    levels += 4 * stride;
    coeff_contexts += 16;
    col -= 4;
  } while (col);
}

static inline void get_4_nz_map_contexts_hor(const uint8_t *levels,
                                             const int width,
                                             const ptrdiff_t *const offsets,
                                             int8_t *coeff_contexts) {
  const int stride = 4 + TX_PAD_HOR;
  const __m128i pos_to_offset_large = _mm_set1_epi8(SIG_COEF_CONTEXTS_2D + 10);
  __m128i pos_to_offset =
      _mm_setr_epi8(SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 0,
                    SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 0,
                    SIG_COEF_CONTEXTS_2D + 5, SIG_COEF_CONTEXTS_2D + 5,
                    SIG_COEF_CONTEXTS_2D + 5, SIG_COEF_CONTEXTS_2D + 5,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10);
  __m128i count;
  __m128i level[5];
  int col = width;

  assert(!(width % 4));

  do {
    load_levels_4x4x5_sse2(levels, stride, offsets, level);
    count = get_coeff_contexts_kernel_sse2(level);
    count = _mm_add_epi8(count, pos_to_offset);
    _mm_store_si128((__m128i *)coeff_contexts, count);
    pos_to_offset = pos_to_offset_large;
    levels += 4 * stride;
    coeff_contexts += 16;
    col -= 4;
  } while (col);
}

static inline void get_8_coeff_contexts_2d(const uint8_t *levels,
                                           const int width,
                                           const ptrdiff_t *const offsets,
                                           int8_t *coeff_contexts) {
  const int stride = 8 + TX_PAD_HOR;
  int8_t *cc = coeff_contexts;
  int col = width;
  __m128i count;
  __m128i level[5];
  __m128i pos_to_offset[3];

  assert(!(width % 2));

  if (width == 8) {
    pos_to_offset[0] =
        _mm_setr_epi8(0, 1, 6, 6, 21, 21, 21, 21, 1, 6, 6, 21, 21, 21, 21, 21);
    pos_to_offset[1] = _mm_setr_epi8(6, 6, 21, 21, 21, 21, 21, 21, 6, 21, 21,
                                     21, 21, 21, 21, 21);
  } else if (width < 8) {
    pos_to_offset[0] = _mm_setr_epi8(0, 11, 6, 6, 21, 21, 21, 21, 11, 11, 6, 21,
                                     21, 21, 21, 21);
    pos_to_offset[1] = _mm_setr_epi8(11, 11, 21, 21, 21, 21, 21, 21, 11, 11, 21,
                                     21, 21, 21, 21, 21);
  } else {
    pos_to_offset[0] = _mm_setr_epi8(0, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
                                     16, 16, 16, 16, 16);
    pos_to_offset[1] = _mm_setr_epi8(6, 6, 21, 21, 21, 21, 21, 21, 6, 21, 21,
                                     21, 21, 21, 21, 21);
  }
  pos_to_offset[2] = _mm_set1_epi8(21);

  do {
    load_levels_8x2x5_sse2(levels, stride, offsets, level);
    count = get_coeff_contexts_kernel_sse2(level);
    count = _mm_add_epi8(count, pos_to_offset[0]);
    _mm_store_si128((__m128i *)cc, count);
    pos_to_offset[0] = pos_to_offset[1];
    pos_to_offset[1] = pos_to_offset[2];
    levels += 2 * stride;
    cc += 16;
    col -= 2;
  } while (col);

  coeff_contexts[0] = 0;
}

static inline void get_8_coeff_contexts_ver(const uint8_t *levels,
                                            const int width,
                                            const ptrdiff_t *const offsets,
                                            int8_t *coeff_contexts) {
  const int stride = 8 + TX_PAD_HOR;
  const __m128i pos_to_offset =
      _mm_setr_epi8(SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 5,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 5,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10);
  int col = width;
  __m128i count;
  __m128i level[5];

  assert(!(width % 2));

  do {
    load_levels_8x2x5_sse2(levels, stride, offsets, level);
    count = get_coeff_contexts_kernel_sse2(level);
    count = _mm_add_epi8(count, pos_to_offset);
    _mm_store_si128((__m128i *)coeff_contexts, count);
    levels += 2 * stride;
    coeff_contexts += 16;
    col -= 2;
  } while (col);
}

static inline void get_8_coeff_contexts_hor(const uint8_t *levels,
                                            const int width,
                                            const ptrdiff_t *const offsets,
                                            int8_t *coeff_contexts) {
  const int stride = 8 + TX_PAD_HOR;
  const __m128i pos_to_offset_large = _mm_set1_epi8(SIG_COEF_CONTEXTS_2D + 10);
  __m128i pos_to_offset =
      _mm_setr_epi8(SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 0,
                    SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 0,
                    SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 0,
                    SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 0,
                    SIG_COEF_CONTEXTS_2D + 5, SIG_COEF_CONTEXTS_2D + 5,
                    SIG_COEF_CONTEXTS_2D + 5, SIG_COEF_CONTEXTS_2D + 5,
                    SIG_COEF_CONTEXTS_2D + 5, SIG_COEF_CONTEXTS_2D + 5,
                    SIG_COEF_CONTEXTS_2D + 5, SIG_COEF_CONTEXTS_2D + 5);
  int col = width;
  __m128i count;
  __m128i level[5];

  assert(!(width % 2));

  do {
    load_levels_8x2x5_sse2(levels, stride, offsets, level);
    count = get_coeff_contexts_kernel_sse2(level);
    count = _mm_add_epi8(count, pos_to_offset);
    _mm_store_si128((__m128i *)coeff_contexts, count);
    pos_to_offset = pos_to_offset_large;
    levels += 2 * stride;
    coeff_contexts += 16;
    col -= 2;
  } while (col);
}

static inline void get_16n_coeff_contexts_2d(const uint8_t *levels,
                                             const int real_width,
                                             const int real_height,
                                             const int width, const int height,
                                             const ptrdiff_t *const offsets,
                                             int8_t *coeff_contexts) {
  const int stride = height + TX_PAD_HOR;
  int8_t *cc = coeff_contexts;
  int col = width;
  __m128i pos_to_offset[5];
  __m128i pos_to_offset_large[3];
  __m128i count;
  __m128i level[5];

  assert(!(height % 16));

  pos_to_offset_large[2] = _mm_set1_epi8(21);
  if (real_width == real_height) {
    pos_to_offset[0] = _mm_setr_epi8(0, 1, 6, 6, 21, 21, 21, 21, 21, 21, 21, 21,
                                     21, 21, 21, 21);
    pos_to_offset[1] = _mm_setr_epi8(1, 6, 6, 21, 21, 21, 21, 21, 21, 21, 21,
                                     21, 21, 21, 21, 21);
    pos_to_offset[2] = _mm_setr_epi8(6, 6, 21, 21, 21, 21, 21, 21, 21, 21, 21,
                                     21, 21, 21, 21, 21);
    pos_to_offset[3] = _mm_setr_epi8(6, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
                                     21, 21, 21, 21, 21);
    pos_to_offset[4] = pos_to_offset_large[0] = pos_to_offset_large[1] =
        pos_to_offset_large[2];
  } else if (real_width < real_height) {
    pos_to_offset[0] = _mm_setr_epi8(0, 11, 6, 6, 21, 21, 21, 21, 21, 21, 21,
                                     21, 21, 21, 21, 21);
    pos_to_offset[1] = _mm_setr_epi8(11, 11, 6, 21, 21, 21, 21, 21, 21, 21, 21,
                                     21, 21, 21, 21, 21);
    pos_to_offset[2] = pos_to_offset[3] = pos_to_offset[4] = _mm_setr_epi8(
        11, 11, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21);
    pos_to_offset_large[0] = pos_to_offset_large[1] = pos_to_offset_large[2];
  } else {  // real_width > real_height
    pos_to_offset[0] = pos_to_offset[1] = _mm_setr_epi8(
        16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16);
    pos_to_offset[2] = _mm_setr_epi8(6, 6, 21, 21, 21, 21, 21, 21, 21, 21, 21,
                                     21, 21, 21, 21, 21);
    pos_to_offset[3] = _mm_setr_epi8(6, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
                                     21, 21, 21, 21, 21);
    pos_to_offset[4] = pos_to_offset_large[2];
    pos_to_offset_large[0] = pos_to_offset_large[1] = _mm_set1_epi8(16);
  }

  do {
    int h = height;

    do {
      load_levels_16x1x5_sse2(levels, stride, offsets, level);
      count = get_coeff_contexts_kernel_sse2(level);
      count = _mm_add_epi8(count, pos_to_offset[0]);
      _mm_store_si128((__m128i *)cc, count);
      levels += 16;
      cc += 16;
      h -= 16;
      pos_to_offset[0] = pos_to_offset_large[0];
    } while (h);

    pos_to_offset[0] = pos_to_offset[1];
    pos_to_offset[1] = pos_to_offset[2];
    pos_to_offset[2] = pos_to_offset[3];
    pos_to_offset[3] = pos_to_offset[4];
    pos_to_offset_large[0] = pos_to_offset_large[1];
    pos_to_offset_large[1] = pos_to_offset_large[2];
    levels += TX_PAD_HOR;
  } while (--col);

  coeff_contexts[0] = 0;
}

static inline void get_16n_coeff_contexts_ver(const uint8_t *levels,
                                              const int width, const int height,
                                              const ptrdiff_t *const offsets,
                                              int8_t *coeff_contexts) {
  const int stride = height + TX_PAD_HOR;
  const __m128i pos_to_offset_large =
      _mm_setr_epi8(SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                    SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10);
  __m128i count;
  __m128i level[5];
  int col = width;

  assert(!(height % 16));

  do {
    __m128i pos_to_offset =
        _mm_setr_epi8(SIG_COEF_CONTEXTS_2D + 0, SIG_COEF_CONTEXTS_2D + 5,
                      SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                      SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                      SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                      SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                      SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                      SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10,
                      SIG_COEF_CONTEXTS_2D + 10, SIG_COEF_CONTEXTS_2D + 10);
    int h = height;

    do {
      load_levels_16x1x5_sse2(levels, stride, offsets, level);
      count = get_coeff_contexts_kernel_sse2(level);
      count = _mm_add_epi8(count, pos_to_offset);
      _mm_store_si128((__m128i *)coeff_contexts, count);
      pos_to_offset = pos_to_offset_large;
      levels += 16;
      coeff_contexts += 16;
      h -= 16;
    } while (h);

    levels += TX_PAD_HOR;
  } while (--col);
}

static inline void get_16n_coeff_contexts_hor(const uint8_t *levels,
                                              const int width, const int height,
                                              const ptrdiff_t *const offsets,
                                              int8_t *coeff_contexts) {
  const int stride = height + TX_PAD_HOR;
  __m128i pos_to_offset[3];
  __m128i count;
  __m128i level[5];
  int col = width;

  assert(!(height % 16));

  pos_to_offset[0] = _mm_set1_epi8(SIG_COEF_CONTEXTS_2D + 0);
  pos_to_offset[1] = _mm_set1_epi8(SIG_COEF_CONTEXTS_2D + 5);
  pos_to_offset[2] = _mm_set1_epi8(SIG_COEF_CONTEXTS_2D + 10);

  do {
    int h = height;

    do {
      load_levels_16x1x5_sse2(levels, stride, offsets, level);
      count = get_coeff_contexts_kernel_sse2(level);
      count = _mm_add_epi8(count, pos_to_offset[0]);
      _mm_store_si128((__m128i *)coeff_contexts, count);
      levels += 16;
      coeff_contexts += 16;
      h -= 16;
    } while (h);

    pos_to_offset[0] = pos_to_offset[1];
    pos_to_offset[1] = pos_to_offset[2];
    levels += TX_PAD_HOR;
  } while (--col);
}

// Note: levels[] must be in the range [0, 127], inclusive.
void av1_get_nz_map_contexts_sse2(const uint8_t *const levels,
                                  const int16_t *const scan, const uint16_t eob,
                                  const TX_SIZE tx_size,
                                  const TX_CLASS tx_class,
                                  int8_t *const coeff_contexts) {
  const int last_idx = eob - 1;
  if (!last_idx) {
    coeff_contexts[0] = 0;
    return;
  }

  const int real_width = tx_size_wide[tx_size];
  const int real_height = tx_size_high[tx_size];
  const int width = get_txb_wide(tx_size);
  const int height = get_txb_high(tx_size);
  const int stride = height + TX_PAD_HOR;
  ptrdiff_t offsets[3];

  /* coeff_contexts must be 16 byte aligned. */
  assert(!((intptr_t)coeff_contexts & 0xf));

  if (tx_class == TX_CLASS_2D) {
    offsets[0] = 0 * stride + 2;
    offsets[1] = 1 * stride + 1;
    offsets[2] = 2 * stride + 0;

    if (height == 4) {
      get_4_nz_map_contexts_2d(levels, width, offsets, coeff_contexts);
    } else if (height == 8) {
      get_8_coeff_contexts_2d(levels, width, offsets, coeff_contexts);
    } else if (height == 16) {
      get_16n_coeff_contexts_2d(levels, real_width, real_height, width, height,
                                offsets, coeff_contexts);
    } else {
      get_16n_coeff_contexts_2d(levels, real_width, real_height, width, height,
                                offsets, coeff_contexts);
    }
  } else if (tx_class == TX_CLASS_HORIZ) {
    offsets[0] = 2 * stride;
    offsets[1] = 3 * stride;
    offsets[2] = 4 * stride;
    if (height == 4) {
      get_4_nz_map_contexts_hor(levels, width, offsets, coeff_contexts);
    } else if (height == 8) {
      get_8_coeff_contexts_hor(levels, width, offsets, coeff_contexts);
    } else {
      get_16n_coeff_contexts_hor(levels, width, height, offsets,
                                 coeff_contexts);
    }
  } else {  // TX_CLASS_VERT
    offsets[0] = 2;
    offsets[1] = 3;
    offsets[2] = 4;
    if (height == 4) {
      get_4_nz_map_contexts_ver(levels, width, offsets, coeff_contexts);
    } else if (height == 8) {
      get_8_coeff_contexts_ver(levels, width, offsets, coeff_contexts);
    } else {
      get_16n_coeff_contexts_ver(levels, width, height, offsets,
                                 coeff_contexts);
    }
  }

  const int bhl = get_txb_bhl(tx_size);
  const int pos = scan[last_idx];
  if (last_idx <= (width << bhl) / 8)
    coeff_contexts[pos] = 1;
  else if (last_idx <= (width << bhl) / 4)
    coeff_contexts[pos] = 2;
  else
    coeff_contexts[pos] = 3;
}