// Copyright 2022 Google Inc. All Rights Reserved.

//

// Use of this source code is governed by a BSD-style license

// that can be found in the COPYING 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.

// -----------------------------------------------------------------------------

//

// Speed-critical functions for Sharp YUV.

//

// Author: Skal (pascal.massimino@gmail.com)

#include "sharpyuv/sharpyuv_dsp.h"

#if defined(WEBP_USE_SSE2)

#include <stdlib.h>

#include <emmintrin.h>

static uint16_t clip_SSE2(int v, int max) {

  return (v < 0) ? 0 : (v > max) ? max : (uint16_t)v;

}

static uint64_t SharpYuvUpdateY_SSE2(const uint16_t* ref, const uint16_t* src,

                                     uint16_t* dst, int len, int bit_depth) {

  const int max_y = (1 << bit_depth) - 1;

  uint64_t diff = 0;

  uint32_t tmp[4];

  int i;

  const __m128i zero = _mm_setzero_si128();

  const __m128i max = _mm_set1_epi16(max_y);

  const __m128i one = _mm_set1_epi16(1);

  __m128i sum = zero;

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

    const __m128i A = _mm_loadu_si128((const __m128i*)(ref + i));

    const __m128i B = _mm_loadu_si128((const __m128i*)(src + i));

    const __m128i C = _mm_loadu_si128((const __m128i*)(dst + i));

    const __m128i D = _mm_sub_epi16(A, B);       // diff_y

    const __m128i E = _mm_cmpgt_epi16(zero, D);  // sign (-1 or 0)

    const __m128i F = _mm_add_epi16(C, D);       // new_y

    const __m128i G = _mm_or_si128(E, one);      // -1 or 1

    const __m128i H = _mm_max_epi16(_mm_min_epi16(F, max), zero);

    const __m128i I = _mm_madd_epi16(D, G);      // sum(abs(...))

    _mm_storeu_si128((__m128i*)(dst + i), H);

    sum = _mm_add_epi32(sum, I);

  }

  _mm_storeu_si128((__m128i*)tmp, sum);

  diff = tmp[3] + tmp[2] + tmp[1] + tmp[0];

  for (; i < len; ++i) {

    const int diff_y = ref[i] - src[i];

    const int new_y = (int)dst[i] + diff_y;

    dst[i] = clip_SSE2(new_y, max_y);

    diff += (uint64_t)abs(diff_y);

  }

  return diff;

}

static void SharpYuvUpdateRGB_SSE2(const int16_t* ref, const int16_t* src,

                                   int16_t* dst, int len) {

  int i = 0;

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

    const __m128i A = _mm_loadu_si128((const __m128i*)(ref + i));

    const __m128i B = _mm_loadu_si128((const __m128i*)(src + i));

    const __m128i C = _mm_loadu_si128((const __m128i*)(dst + i));

    const __m128i D = _mm_sub_epi16(A, B);   // diff_uv

    const __m128i E = _mm_add_epi16(C, D);   // new_uv

    _mm_storeu_si128((__m128i*)(dst + i), E);

  }

  for (; i < len; ++i) {

    const int diff_uv = ref[i] - src[i];

    dst[i] += diff_uv;

  }

}

static void SharpYuvFilterRow16_SSE2(const int16_t* A, const int16_t* B,

                                     int len, const uint16_t* best_y,

                                     uint16_t* out, int bit_depth) {

  const int max_y = (1 << bit_depth) - 1;

  int i;

  const __m128i kCst8 = _mm_set1_epi16(8);

  const __m128i max = _mm_set1_epi16(max_y);

  const __m128i zero = _mm_setzero_si128();

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

    const __m128i a0 = _mm_loadu_si128((const __m128i*)(A + i + 0));

    const __m128i a1 = _mm_loadu_si128((const __m128i*)(A + i + 1));

    const __m128i b0 = _mm_loadu_si128((const __m128i*)(B + i + 0));

    const __m128i b1 = _mm_loadu_si128((const __m128i*)(B + i + 1));

    const __m128i a0b1 = _mm_add_epi16(a0, b1);

    const __m128i a1b0 = _mm_add_epi16(a1, b0);

    const __m128i a0a1b0b1 = _mm_add_epi16(a0b1, a1b0);  // A0+A1+B0+B1

    const __m128i a0a1b0b1_8 = _mm_add_epi16(a0a1b0b1, kCst8);

    const __m128i a0b1_2 = _mm_add_epi16(a0b1, a0b1);    // 2*(A0+B1)

    const __m128i a1b0_2 = _mm_add_epi16(a1b0, a1b0);    // 2*(A1+B0)

    const __m128i c0 = _mm_srai_epi16(_mm_add_epi16(a0b1_2, a0a1b0b1_8), 3);

    const __m128i c1 = _mm_srai_epi16(_mm_add_epi16(a1b0_2, a0a1b0b1_8), 3);

    const __m128i d0 = _mm_add_epi16(c1, a0);

    const __m128i d1 = _mm_add_epi16(c0, a1);

    const __m128i e0 = _mm_srai_epi16(d0, 1);

    const __m128i e1 = _mm_srai_epi16(d1, 1);

    const __m128i f0 = _mm_unpacklo_epi16(e0, e1);

    const __m128i f1 = _mm_unpackhi_epi16(e0, e1);

    const __m128i g0 = _mm_loadu_si128((const __m128i*)(best_y + 2 * i + 0));

    const __m128i g1 = _mm_loadu_si128((const __m128i*)(best_y + 2 * i + 8));

    const __m128i h0 = _mm_add_epi16(g0, f0);

    const __m128i h1 = _mm_add_epi16(g1, f1);

    const __m128i i0 = _mm_max_epi16(_mm_min_epi16(h0, max), zero);

    const __m128i i1 = _mm_max_epi16(_mm_min_epi16(h1, max), zero);

    _mm_storeu_si128((__m128i*)(out + 2 * i + 0), i0);

    _mm_storeu_si128((__m128i*)(out + 2 * i + 8), i1);

  }

  for (; i < len; ++i) {

    //   (9 * A0 + 3 * A1 + 3 * B0 + B1 + 8) >> 4 =

    // = (8 * A0 + 2 * (A1 + B0) + (A0 + A1 + B0 + B1 + 8)) >> 4

    // We reuse the common sub-expressions.

    const int a0b1 = A[i + 0] + B[i + 1];

    const int a1b0 = A[i + 1] + B[i + 0];

    const int a0a1b0b1 = a0b1 + a1b0 + 8;

    const int v0 = (8 * A[i + 0] + 2 * a1b0 + a0a1b0b1) >> 4;

    const int v1 = (8 * A[i + 1] + 2 * a0b1 + a0a1b0b1) >> 4;

    out[2 * i + 0] = clip_SSE2(best_y[2 * i + 0] + v0, max_y);

    out[2 * i + 1] = clip_SSE2(best_y[2 * i + 1] + v1, max_y);

  }

}

static WEBP_INLINE __m128i s16_to_s32(__m128i in) {

  return _mm_srai_epi32(_mm_unpacklo_epi16(in, in), 16);

}

static void SharpYuvFilterRow32_SSE2(const int16_t* A, const int16_t* B,

                                     int len, const uint16_t* best_y,

                                     uint16_t* out, int bit_depth) {

  const int max_y = (1 << bit_depth) - 1;

  int i;

  const __m128i kCst8 = _mm_set1_epi32(8);

  const __m128i max = _mm_set1_epi16(max_y);

  const __m128i zero = _mm_setzero_si128();

  for (i = 0; i + 4 <= len; i += 4) {

    const __m128i a0 = s16_to_s32(_mm_loadl_epi64((const __m128i*)(A + i + 0)));

    const __m128i a1 = s16_to_s32(_mm_loadl_epi64((const __m128i*)(A + i + 1)));

    const __m128i b0 = s16_to_s32(_mm_loadl_epi64((const __m128i*)(B + i + 0)));

    const __m128i b1 = s16_to_s32(_mm_loadl_epi64((const __m128i*)(B + i + 1)));

    const __m128i a0b1 = _mm_add_epi32(a0, b1);

    const __m128i a1b0 = _mm_add_epi32(a1, b0);

    const __m128i a0a1b0b1 = _mm_add_epi32(a0b1, a1b0);  // A0+A1+B0+B1

    const __m128i a0a1b0b1_8 = _mm_add_epi32(a0a1b0b1, kCst8);

    const __m128i a0b1_2 = _mm_add_epi32(a0b1, a0b1);  // 2*(A0+B1)

    const __m128i a1b0_2 = _mm_add_epi32(a1b0, a1b0);  // 2*(A1+B0)

    const __m128i c0 = _mm_srai_epi32(_mm_add_epi32(a0b1_2, a0a1b0b1_8), 3);

    const __m128i c1 = _mm_srai_epi32(_mm_add_epi32(a1b0_2, a0a1b0b1_8), 3);

    const __m128i d0 = _mm_add_epi32(c1, a0);

    const __m128i d1 = _mm_add_epi32(c0, a1);

    const __m128i e0 = _mm_srai_epi32(d0, 1);

    const __m128i e1 = _mm_srai_epi32(d1, 1);

    const __m128i f0 = _mm_unpacklo_epi32(e0, e1);

    const __m128i f1 = _mm_unpackhi_epi32(e0, e1);

    const __m128i g = _mm_loadu_si128((const __m128i*)(best_y + 2 * i + 0));

    const __m128i h_16 = _mm_add_epi16(g, _mm_packs_epi32(f0, f1));

    const __m128i final = _mm_max_epi16(_mm_min_epi16(h_16, max), zero);

    _mm_storeu_si128((__m128i*)(out + 2 * i + 0), final);

  }

  for (; i < len; ++i) {

    //   (9 * A0 + 3 * A1 + 3 * B0 + B1 + 8) >> 4 =

    // = (8 * A0 + 2 * (A1 + B0) + (A0 + A1 + B0 + B1 + 8)) >> 4

    // We reuse the common sub-expressions.

    const int a0b1 = A[i + 0] + B[i + 1];

    const int a1b0 = A[i + 1] + B[i + 0];

    const int a0a1b0b1 = a0b1 + a1b0 + 8;

    const int v0 = (8 * A[i + 0] + 2 * a1b0 + a0a1b0b1) >> 4;

    const int v1 = (8 * A[i + 1] + 2 * a0b1 + a0a1b0b1) >> 4;

    out[2 * i + 0] = clip_SSE2(best_y[2 * i + 0] + v0, max_y);

    out[2 * i + 1] = clip_SSE2(best_y[2 * i + 1] + v1, max_y);

  }

}

static void SharpYuvFilterRow_SSE2(const int16_t* A, const int16_t* B, int len,

                                   const uint16_t* best_y, uint16_t* out,

                                   int bit_depth) {

  if (bit_depth <= 10) {

    SharpYuvFilterRow16_SSE2(A, B, len, best_y, out, bit_depth);

  } else {

    SharpYuvFilterRow32_SSE2(A, B, len, best_y, out, bit_depth);

  }

}

//------------------------------------------------------------------------------

extern void InitSharpYuvSSE2(void);

WEBP_TSAN_IGNORE_FUNCTION void InitSharpYuvSSE2(void) {

  SharpYuvUpdateY = SharpYuvUpdateY_SSE2;

  SharpYuvUpdateRGB = SharpYuvUpdateRGB_SSE2;

  SharpYuvFilterRow = SharpYuvFilterRow_SSE2;

}

#else  // !WEBP_USE_SSE2

extern void InitSharpYuvSSE2(void);

void InitSharpYuvSSE2(void) {}

#endif  // WEBP_USE_SSE2