// Copyright 2014 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.

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

//

// SSE2 variant of methods for lossless decoder

//

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

#include "src/dsp/dsp.h"

#if defined(WEBP_USE_SSE2)

#include <emmintrin.h>

#include <string.h>

#include "src/dsp/common_sse2.h"

#include "src/dsp/cpu.h"

#include "src/dsp/lossless.h"

#include "src/dsp/lossless_common.h"

#include "src/webp/format_constants.h"

#include "src/webp/types.h"

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

// Predictor Transform

static WEBP_INLINE uint32_t ClampedAddSubtractFull_SSE2(uint32_t c0,

                                                        uint32_t c1,

                                                        uint32_t c2) {

  const __m128i zero = _mm_setzero_si128();

  const __m128i C0 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c0), zero);

  const __m128i C1 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c1), zero);

  const __m128i C2 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c2), zero);

  const __m128i V1 = _mm_add_epi16(C0, C1);

  const __m128i V2 = _mm_sub_epi16(V1, C2);

  const __m128i b = _mm_packus_epi16(V2, V2);

  return (uint32_t)_mm_cvtsi128_si32(b);

}

static WEBP_INLINE uint32_t ClampedAddSubtractHalf_SSE2(uint32_t c0,

                                                        uint32_t c1,

                                                        uint32_t c2) {

  const __m128i zero = _mm_setzero_si128();

  const __m128i C0 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c0), zero);

  const __m128i C1 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c1), zero);

  const __m128i B0 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c2), zero);

  const __m128i avg = _mm_add_epi16(C1, C0);

  const __m128i A0 = _mm_srli_epi16(avg, 1);

  const __m128i A1 = _mm_sub_epi16(A0, B0);

  const __m128i BgtA = _mm_cmpgt_epi16(B0, A0);

  const __m128i A2 = _mm_sub_epi16(A1, BgtA);

  const __m128i A3 = _mm_srai_epi16(A2, 1);

  const __m128i A4 = _mm_add_epi16(A0, A3);

  const __m128i A5 = _mm_packus_epi16(A4, A4);

  return (uint32_t)_mm_cvtsi128_si32(A5);

}

static WEBP_INLINE uint32_t Select_SSE2(uint32_t a, uint32_t b, uint32_t c) {

  int pa_minus_pb;

  const __m128i zero = _mm_setzero_si128();

  const __m128i A0 = _mm_cvtsi32_si128((int)a);

  const __m128i B0 = _mm_cvtsi32_si128((int)b);

  const __m128i C0 = _mm_cvtsi32_si128((int)c);

  const __m128i AC0 = _mm_subs_epu8(A0, C0);

  const __m128i CA0 = _mm_subs_epu8(C0, A0);

  const __m128i BC0 = _mm_subs_epu8(B0, C0);

  const __m128i CB0 = _mm_subs_epu8(C0, B0);

  const __m128i AC = _mm_or_si128(AC0, CA0);

  const __m128i BC = _mm_or_si128(BC0, CB0);

  const __m128i pa = _mm_unpacklo_epi8(AC, zero);  // |a - c|

  const __m128i pb = _mm_unpacklo_epi8(BC, zero);  // |b - c|

  const __m128i diff = _mm_sub_epi16(pb, pa);

  {

    int16_t out[8];

    _mm_storeu_si128((__m128i*)out, diff);

    pa_minus_pb = out[0] + out[1] + out[2] + out[3];

  }

  return (pa_minus_pb <= 0) ? a : b;

}

static WEBP_INLINE void Average2_m128i(const __m128i* const a0,

                                       const __m128i* const a1,

                                       __m128i* const avg) {

  // (a + b) >> 1 = ((a + b + 1) >> 1) - ((a ^ b) & 1)

  const __m128i ones = _mm_set1_epi8(1);

  const __m128i avg1 = _mm_avg_epu8(*a0, *a1);

  const __m128i one = _mm_and_si128(_mm_xor_si128(*a0, *a1), ones);

  *avg = _mm_sub_epi8(avg1, one);

}

static WEBP_INLINE void Average2_uint32_SSE2(const uint32_t a0,

                                             const uint32_t a1,

                                             __m128i* const avg) {

  // (a + b) >> 1 = ((a + b + 1) >> 1) - ((a ^ b) & 1)

  const __m128i ones = _mm_set1_epi8(1);

  const __m128i A0 = _mm_cvtsi32_si128((int)a0);

  const __m128i A1 = _mm_cvtsi32_si128((int)a1);

  const __m128i avg1 = _mm_avg_epu8(A0, A1);

  const __m128i one = _mm_and_si128(_mm_xor_si128(A0, A1), ones);

  *avg = _mm_sub_epi8(avg1, one);

}

static WEBP_INLINE __m128i Average2_uint32_16_SSE2(uint32_t a0, uint32_t a1) {

  const __m128i zero = _mm_setzero_si128();

  const __m128i A0 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)a0), zero);

  const __m128i A1 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)a1), zero);

  const __m128i sum = _mm_add_epi16(A1, A0);

  return _mm_srli_epi16(sum, 1);

}

static WEBP_INLINE uint32_t Average2_SSE2(uint32_t a0, uint32_t a1) {

  __m128i output;

  Average2_uint32_SSE2(a0, a1, &output);

  return (uint32_t)_mm_cvtsi128_si32(output);

}

static WEBP_INLINE uint32_t Average3_SSE2(uint32_t a0, uint32_t a1,

                                          uint32_t a2) {

  const __m128i zero = _mm_setzero_si128();

  const __m128i avg1 = Average2_uint32_16_SSE2(a0, a2);

  const __m128i A1 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)a1), zero);

  const __m128i sum = _mm_add_epi16(avg1, A1);

  const __m128i avg2 = _mm_srli_epi16(sum, 1);

  const __m128i A2 = _mm_packus_epi16(avg2, avg2);

  return (uint32_t)_mm_cvtsi128_si32(A2);

}

static WEBP_INLINE uint32_t Average4_SSE2(uint32_t a0, uint32_t a1,

                                          uint32_t a2, uint32_t a3) {

  const __m128i avg1 = Average2_uint32_16_SSE2(a0, a1);

  const __m128i avg2 = Average2_uint32_16_SSE2(a2, a3);

  const __m128i sum = _mm_add_epi16(avg2, avg1);

  const __m128i avg3 = _mm_srli_epi16(sum, 1);

  const __m128i A0 = _mm_packus_epi16(avg3, avg3);

  return (uint32_t)_mm_cvtsi128_si32(A0);

}

static uint32_t Predictor5_SSE2(const uint32_t* const left,

                                const uint32_t* const top) {

  const uint32_t pred = Average3_SSE2(*left, top[0], top[1]);

  return pred;

}

static uint32_t Predictor6_SSE2(const uint32_t* const left,

                                const uint32_t* const top) {

  const uint32_t pred = Average2_SSE2(*left, top[-1]);

  return pred;

}

static uint32_t Predictor7_SSE2(const uint32_t* const left,

                                const uint32_t* const top) {

  const uint32_t pred = Average2_SSE2(*left, top[0]);

  return pred;

}

static uint32_t Predictor8_SSE2(const uint32_t* const left,

                                const uint32_t* const top) {

  const uint32_t pred = Average2_SSE2(top[-1], top[0]);

  (void)left;

  return pred;

}

static uint32_t Predictor9_SSE2(const uint32_t* const left,

                                const uint32_t* const top) {

  const uint32_t pred = Average2_SSE2(top[0], top[1]);

  (void)left;

  return pred;

}

static uint32_t Predictor10_SSE2(const uint32_t* const left,

                                 const uint32_t* const top) {

  const uint32_t pred = Average4_SSE2(*left, top[-1], top[0], top[1]);

  return pred;

}

static uint32_t Predictor11_SSE2(const uint32_t* const left,

                                 const uint32_t* const top) {

  const uint32_t pred = Select_SSE2(top[0], *left, top[-1]);

  return pred;

}

static uint32_t Predictor12_SSE2(const uint32_t* const left,

                                 const uint32_t* const top) {

  const uint32_t pred = ClampedAddSubtractFull_SSE2(*left, top[0], top[-1]);

  return pred;

}

static uint32_t Predictor13_SSE2(const uint32_t* const left,

                                 const uint32_t* const top) {

  const uint32_t pred = ClampedAddSubtractHalf_SSE2(*left, top[0], top[-1]);

  return pred;

}

// Batch versions of those functions.

// Predictor0: ARGB_BLACK.

static void PredictorAdd0_SSE2(const uint32_t* in, const uint32_t* upper,

                               int num_pixels, uint32_t* WEBP_RESTRICT out) {

  int i;

  const __m128i black = _mm_set1_epi32((int)ARGB_BLACK);

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

    const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);

    const __m128i res = _mm_add_epi8(src, black);

    _mm_storeu_si128((__m128i*)&out[i], res);

  }

  if (i != num_pixels) {

    VP8LPredictorsAdd_C[0](in + i, NULL, num_pixels - i, out + i);

  }

  (void)upper;

}

// Predictor1: left.

static void PredictorAdd1_SSE2(const uint32_t* in, const uint32_t* upper,

                               int num_pixels, uint32_t* WEBP_RESTRICT out) {

  int i;

  __m128i prev = _mm_set1_epi32((int)out[-1]);

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

    // a | b | c | d

    const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);

    // 0 | a | b | c

    const __m128i shift0 = _mm_slli_si128(src, 4);

    // a | a + b | b + c | c + d

    const __m128i sum0 = _mm_add_epi8(src, shift0);

    // 0 | 0 | a | a + b

    const __m128i shift1 = _mm_slli_si128(sum0, 8);

    // a | a + b | a + b + c | a + b + c + d

    const __m128i sum1 = _mm_add_epi8(sum0, shift1);

    const __m128i res = _mm_add_epi8(sum1, prev);

    _mm_storeu_si128((__m128i*)&out[i], res);

    // replicate prev output on the four lanes

    prev = _mm_shuffle_epi32(res, (3 << 0) | (3 << 2) | (3 << 4) | (3 << 6));

  }

  if (i != num_pixels) {

    VP8LPredictorsAdd_C[1](in + i, upper + i, num_pixels - i, out + i);

  }

}

// Macro that adds 32-bit integers from IN using mod 256 arithmetic

// per 8 bit channel.

#define GENERATE_PREDICTOR_1(X, IN)                                           \

static void PredictorAdd##X##_SSE2(const uint32_t* in, const uint32_t* upper, \

                                   int num_pixels,                            \

                                   uint32_t* WEBP_RESTRICT out) {             \

  int i;                                                                      \

  for (i = 0; i + 4 <= num_pixels; i += 4) {                                  \

    const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);              \

    const __m128i other = _mm_loadu_si128((const __m128i*)&(IN));             \

    const __m128i res = _mm_add_epi8(src, other);                             \

    _mm_storeu_si128((__m128i*)&out[i], res);                                 \

  }                                                                           \

  if (i != num_pixels) {                                                      \

    VP8LPredictorsAdd_C[(X)](in + i, upper + i, num_pixels - i, out + i);     \

  }                                                                           \

}

Unexecuted instantiation: lossless_sse2.c:PredictorAdd2_SSE2

Unexecuted instantiation: lossless_sse2.c:PredictorAdd3_SSE2

Unexecuted instantiation: lossless_sse2.c:PredictorAdd4_SSE2

// Predictor2: Top.

GENERATE_PREDICTOR_1(2, upper[i])

// Predictor3: Top-right.

GENERATE_PREDICTOR_1(3, upper[i + 1])

// Predictor4: Top-left.

GENERATE_PREDICTOR_1(4, upper[i - 1])

#undef GENERATE_PREDICTOR_1

// Due to averages with integers, values cannot be accumulated in parallel for

// predictors 5 to 7.

GENERATE_PREDICTOR_ADD(Predictor5_SSE2, PredictorAdd5_SSE2)

GENERATE_PREDICTOR_ADD(Predictor6_SSE2, PredictorAdd6_SSE2)

GENERATE_PREDICTOR_ADD(Predictor7_SSE2, PredictorAdd7_SSE2)

#define GENERATE_PREDICTOR_2(X, IN)                                           \

static void PredictorAdd##X##_SSE2(const uint32_t* in, const uint32_t* upper, \

                                   int num_pixels,                            \

                                   uint32_t* WEBP_RESTRICT out) {             \

  int i;                                                                      \

  for (i = 0; i + 4 <= num_pixels; i += 4) {                                  \

    const __m128i Tother = _mm_loadu_si128((const __m128i*)&(IN));            \

    const __m128i T = _mm_loadu_si128((const __m128i*)&upper[i]);             \

    const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);              \

    __m128i avg, res;                                                         \

    Average2_m128i(&T, &Tother, &avg);                                        \

    res = _mm_add_epi8(avg, src);                                             \

    _mm_storeu_si128((__m128i*)&out[i], res);                                 \

  }                                                                           \

  if (i != num_pixels) {                                                      \

    VP8LPredictorsAdd_C[(X)](in + i, upper + i, num_pixels - i, out + i);     \

  }                                                                           \

}

Unexecuted instantiation: lossless_sse2.c:PredictorAdd8_SSE2

Unexecuted instantiation: lossless_sse2.c:PredictorAdd9_SSE2

// Predictor8: average TL T.

GENERATE_PREDICTOR_2(8, upper[i - 1])

// Predictor9: average T TR.

GENERATE_PREDICTOR_2(9, upper[i + 1])

#undef GENERATE_PREDICTOR_2

// Predictor10: average of (average of (L,TL), average of (T, TR)).

#define DO_PRED10(OUT) do {                         \

  __m128i avgLTL, avg;                              \

  Average2_m128i(&L, &TL, &avgLTL);                 \

  Average2_m128i(&avgTTR, &avgLTL, &avg);           \

  L = _mm_add_epi8(avg, src);                       \

  out[i + (OUT)] = (uint32_t)_mm_cvtsi128_si32(L);  \

} while (0)

#define DO_PRED10_SHIFT do {                                  \

  /* Rotate the pre-computed values for the next iteration.*/ \

  avgTTR = _mm_srli_si128(avgTTR, 4);                         \

  TL = _mm_srli_si128(TL, 4);                                 \

  src = _mm_srli_si128(src, 4);                               \

} while (0)

static void PredictorAdd10_SSE2(const uint32_t* in, const uint32_t* upper,

                                int num_pixels, uint32_t* WEBP_RESTRICT out) {

  int i;

  __m128i L = _mm_cvtsi32_si128((int)out[-1]);

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

    __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);

    __m128i TL = _mm_loadu_si128((const __m128i*)&upper[i - 1]);

    const __m128i T = _mm_loadu_si128((const __m128i*)&upper[i]);

    const __m128i TR = _mm_loadu_si128((const __m128i*)&upper[i + 1]);

    __m128i avgTTR;

    Average2_m128i(&T, &TR, &avgTTR);

    DO_PRED10(0);

    DO_PRED10_SHIFT;

    DO_PRED10(1);

    DO_PRED10_SHIFT;

    DO_PRED10(2);

    DO_PRED10_SHIFT;

    DO_PRED10(3);

  }

  if (i != num_pixels) {

    VP8LPredictorsAdd_C[10](in + i, upper + i, num_pixels - i, out + i);

  }

}

#undef DO_PRED10

#undef DO_PRED10_SHIFT

// Predictor11: select.

#define DO_PRED11(OUT) do {                                            \

  const __m128i L_lo = _mm_unpacklo_epi32(L, T);                       \

  const __m128i TL_lo = _mm_unpacklo_epi32(TL, T);                     \

  const __m128i pb = _mm_sad_epu8(L_lo, TL_lo); /* pb = sum |L-TL|*/   \

  const __m128i mask = _mm_cmpgt_epi32(pb, pa);                        \

  const __m128i A = _mm_and_si128(mask, L);                            \

  const __m128i B = _mm_andnot_si128(mask, T);                         \

  const __m128i pred = _mm_or_si128(A, B); /* pred = (pa > b)? L : T*/ \

  L = _mm_add_epi8(src, pred);                                         \

  out[i + (OUT)] = (uint32_t)_mm_cvtsi128_si32(L);                     \

} while (0)

#define DO_PRED11_SHIFT do {                                \

  /* Shift the pre-computed value for the next iteration.*/ \

  T = _mm_srli_si128(T, 4);                                 \

  TL = _mm_srli_si128(TL, 4);                               \

  src = _mm_srli_si128(src, 4);                             \

  pa = _mm_srli_si128(pa, 4);                               \

} while (0)

static void PredictorAdd11_SSE2(const uint32_t* in, const uint32_t* upper,

                                int num_pixels, uint32_t* WEBP_RESTRICT out) {

  int i;

  __m128i pa;

  __m128i L = _mm_cvtsi32_si128((int)out[-1]);

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

    __m128i T = _mm_loadu_si128((const __m128i*)&upper[i]);

    __m128i TL = _mm_loadu_si128((const __m128i*)&upper[i - 1]);

    __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);

    {

      // We can unpack with any value on the upper 32 bits, provided it's the

      // same on both operands (so that their sum of abs diff is zero). Here we

      // use T.

      const __m128i T_lo = _mm_unpacklo_epi32(T, T);

      const __m128i TL_lo = _mm_unpacklo_epi32(TL, T);

      const __m128i T_hi = _mm_unpackhi_epi32(T, T);

      const __m128i TL_hi = _mm_unpackhi_epi32(TL, T);

      const __m128i s_lo = _mm_sad_epu8(T_lo, TL_lo);

      const __m128i s_hi = _mm_sad_epu8(T_hi, TL_hi);

      pa = _mm_packs_epi32(s_lo, s_hi);  // pa = sum |T-TL|

    }

    DO_PRED11(0);

    DO_PRED11_SHIFT;

    DO_PRED11(1);

    DO_PRED11_SHIFT;

    DO_PRED11(2);

    DO_PRED11_SHIFT;

    DO_PRED11(3);

  }

  if (i != num_pixels) {

    VP8LPredictorsAdd_C[11](in + i, upper + i, num_pixels - i, out + i);

  }

}

#undef DO_PRED11

#undef DO_PRED11_SHIFT

// Predictor12: ClampedAddSubtractFull.

#define DO_PRED12(DIFF, LANE, OUT) do {              \

  const __m128i all = _mm_add_epi16(L, (DIFF));      \

  const __m128i alls = _mm_packus_epi16(all, all);   \

  const __m128i res = _mm_add_epi8(src, alls);       \

  out[i + (OUT)] = (uint32_t)_mm_cvtsi128_si32(res); \

  L = _mm_unpacklo_epi8(res, zero);                  \

} while (0)

#define DO_PRED12_SHIFT(DIFF, LANE) do {                    \

  /* Shift the pre-computed value for the next iteration.*/ \

  if ((LANE) == 0) (DIFF) = _mm_srli_si128((DIFF), 8);      \

  src = _mm_srli_si128(src, 4);                             \

} while (0)

static void PredictorAdd12_SSE2(const uint32_t* in, const uint32_t* upper,

                                int num_pixels, uint32_t* WEBP_RESTRICT out) {

  int i;

  const __m128i zero = _mm_setzero_si128();

  const __m128i L8 = _mm_cvtsi32_si128((int)out[-1]);

  __m128i L = _mm_unpacklo_epi8(L8, zero);

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

    // Load 4 pixels at a time.

    __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);

    const __m128i T = _mm_loadu_si128((const __m128i*)&upper[i]);

    const __m128i T_lo = _mm_unpacklo_epi8(T, zero);

    const __m128i T_hi = _mm_unpackhi_epi8(T, zero);

    const __m128i TL = _mm_loadu_si128((const __m128i*)&upper[i - 1]);

    const __m128i TL_lo = _mm_unpacklo_epi8(TL, zero);

    const __m128i TL_hi = _mm_unpackhi_epi8(TL, zero);

    __m128i diff_lo = _mm_sub_epi16(T_lo, TL_lo);

    __m128i diff_hi = _mm_sub_epi16(T_hi, TL_hi);

    DO_PRED12(diff_lo, 0, 0);

    DO_PRED12_SHIFT(diff_lo, 0);

    DO_PRED12(diff_lo, 1, 1);

    DO_PRED12_SHIFT(diff_lo, 1);

    DO_PRED12(diff_hi, 0, 2);

    DO_PRED12_SHIFT(diff_hi, 0);

    DO_PRED12(diff_hi, 1, 3);

  }

  if (i != num_pixels) {

    VP8LPredictorsAdd_C[12](in + i, upper + i, num_pixels - i, out + i);

  }

}

#undef DO_PRED12

#undef DO_PRED12_SHIFT

// Due to averages with integers, values cannot be accumulated in parallel for

// predictors 13.

GENERATE_PREDICTOR_ADD(Predictor13_SSE2, PredictorAdd13_SSE2)

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

// Subtract-Green Transform

static void AddGreenToBlueAndRed_SSE2(const uint32_t* const src, int num_pixels,

                                      uint32_t* dst) {

  int i;

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

    const __m128i in = _mm_loadu_si128((const __m128i*)&src[i]); // argb

    const __m128i A = _mm_srli_epi16(in, 8);     // 0 a 0 g

    const __m128i B = _mm_shufflelo_epi16(A, _MM_SHUFFLE(2, 2, 0, 0));

    const __m128i C = _mm_shufflehi_epi16(B, _MM_SHUFFLE(2, 2, 0, 0));  // 0g0g

    const __m128i out = _mm_add_epi8(in, C);

    _mm_storeu_si128((__m128i*)&dst[i], out);

  }

  // fallthrough and finish off with plain-C

  if (i != num_pixels) {

    VP8LAddGreenToBlueAndRed_C(src + i, num_pixels - i, dst + i);

  }

}

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

// Color Transform

static void TransformColorInverse_SSE2(const VP8LMultipliers* const m,

                                       const uint32_t* const src,

                                       int num_pixels, uint32_t* dst) {

// sign-extended multiplying constants, pre-shifted by 5.

#define CST(X)  (((int16_t)(m->X << 8)) >> 5)   // sign-extend

#define MK_CST_16(HI, LO) \

  _mm_set1_epi32((int)(((uint32_t)(HI) << 16) | ((LO) & 0xffff)))

  const __m128i mults_rb = MK_CST_16(CST(green_to_red), CST(green_to_blue));

  const __m128i mults_b2 = MK_CST_16(CST(red_to_blue), 0);

#undef MK_CST_16

#undef CST

  const __m128i mask_ag = _mm_set1_epi32((int)0xff00ff00);  // alpha-green masks

  int i;

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

    const __m128i in = _mm_loadu_si128((const __m128i*)&src[i]); // argb

    const __m128i A = _mm_and_si128(in, mask_ag);     // a   0   g   0

    const __m128i B = _mm_shufflelo_epi16(A, _MM_SHUFFLE(2, 2, 0, 0));

    const __m128i C = _mm_shufflehi_epi16(B, _MM_SHUFFLE(2, 2, 0, 0));  // g0g0

    const __m128i D = _mm_mulhi_epi16(C, mults_rb);    // x dr  x db1

    const __m128i E = _mm_add_epi8(in, D);             // x r'  x   b'

    const __m128i F = _mm_slli_epi16(E, 8);            // r' 0   b' 0

    const __m128i G = _mm_mulhi_epi16(F, mults_b2);    // x db2  0  0

    const __m128i H = _mm_srli_epi32(G, 8);            // 0  x db2  0

    const __m128i I = _mm_add_epi8(H, F);              // r' x  b'' 0

    const __m128i J = _mm_srli_epi16(I, 8);            // 0  r'  0  b''

    const __m128i out = _mm_or_si128(J, A);

    _mm_storeu_si128((__m128i*)&dst[i], out);

  }

  // Fall-back to C-version for left-overs.

  if (i != num_pixels) {

    VP8LTransformColorInverse_C(m, src + i, num_pixels - i, dst + i);

  }

}

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

// Color-space conversion functions

static void ConvertBGRAToRGB_SSE2(const uint32_t* WEBP_RESTRICT src,

                                  int num_pixels, uint8_t* WEBP_RESTRICT dst) {

  const __m128i* in = (const __m128i*)src;

  __m128i* out = (__m128i*)dst;

  while (num_pixels >= 32) {

    // Load the BGRA buffers.

    __m128i in0 = _mm_loadu_si128(in + 0);

    __m128i in1 = _mm_loadu_si128(in + 1);

    __m128i in2 = _mm_loadu_si128(in + 2);

    __m128i in3 = _mm_loadu_si128(in + 3);

    __m128i in4 = _mm_loadu_si128(in + 4);

    __m128i in5 = _mm_loadu_si128(in + 5);

    __m128i in6 = _mm_loadu_si128(in + 6);

    __m128i in7 = _mm_loadu_si128(in + 7);

    VP8L32bToPlanar_SSE2(&in0, &in1, &in2, &in3);

    VP8L32bToPlanar_SSE2(&in4, &in5, &in6, &in7);

    // At this points, in1/in5 contains red only, in2/in6 green only ...

    // Pack the colors in 24b RGB.

    VP8PlanarTo24b_SSE2(&in1, &in5, &in2, &in6, &in3, &in7);

    _mm_storeu_si128(out + 0, in1);

    _mm_storeu_si128(out + 1, in5);

    _mm_storeu_si128(out + 2, in2);

    _mm_storeu_si128(out + 3, in6);

    _mm_storeu_si128(out + 4, in3);

    _mm_storeu_si128(out + 5, in7);

    in += 8;

    out += 6;

    num_pixels -= 32;

  }

  // left-overs

  if (num_pixels > 0) {

    VP8LConvertBGRAToRGB_C((const uint32_t*)in, num_pixels, (uint8_t*)out);

  }

}

static void ConvertBGRAToRGBA_SSE2(const uint32_t* WEBP_RESTRICT src,

                                   int num_pixels, uint8_t* WEBP_RESTRICT dst) {

  const __m128i red_blue_mask = _mm_set1_epi32(0x00ff00ff);

  const __m128i* in = (const __m128i*)src;

  __m128i* out = (__m128i*)dst;

  while (num_pixels >= 8) {

    const __m128i A1 = _mm_loadu_si128(in++);

    const __m128i A2 = _mm_loadu_si128(in++);

    const __m128i B1 = _mm_and_si128(A1, red_blue_mask);     // R 0 B 0

    const __m128i B2 = _mm_and_si128(A2, red_blue_mask);     // R 0 B 0

    const __m128i C1 = _mm_andnot_si128(red_blue_mask, A1);  // 0 G 0 A

    const __m128i C2 = _mm_andnot_si128(red_blue_mask, A2);  // 0 G 0 A

    const __m128i D1 = _mm_shufflelo_epi16(B1, _MM_SHUFFLE(2, 3, 0, 1));

    const __m128i D2 = _mm_shufflelo_epi16(B2, _MM_SHUFFLE(2, 3, 0, 1));

    const __m128i E1 = _mm_shufflehi_epi16(D1, _MM_SHUFFLE(2, 3, 0, 1));

    const __m128i E2 = _mm_shufflehi_epi16(D2, _MM_SHUFFLE(2, 3, 0, 1));

    const __m128i F1 = _mm_or_si128(E1, C1);

    const __m128i F2 = _mm_or_si128(E2, C2);

    _mm_storeu_si128(out++, F1);

    _mm_storeu_si128(out++, F2);

    num_pixels -= 8;

  }

  // left-overs

  if (num_pixels > 0) {

    VP8LConvertBGRAToRGBA_C((const uint32_t*)in, num_pixels, (uint8_t*)out);

  }

}

static void ConvertBGRAToRGBA4444_SSE2(const uint32_t* WEBP_RESTRICT src,

                                       int num_pixels,

                                       uint8_t* WEBP_RESTRICT dst) {

  const __m128i mask_0x0f = _mm_set1_epi8(0x0f);

  const __m128i mask_0xf0 = _mm_set1_epi8((char)0xf0);

  const __m128i* in = (const __m128i*)src;

  __m128i* out = (__m128i*)dst;

  while (num_pixels >= 8) {

    const __m128i bgra0 = _mm_loadu_si128(in++);     // bgra0|bgra1|bgra2|bgra3

    const __m128i bgra4 = _mm_loadu_si128(in++);     // bgra4|bgra5|bgra6|bgra7

    const __m128i v0l = _mm_unpacklo_epi8(bgra0, bgra4);  // b0b4g0g4r0r4a0a4...

    const __m128i v0h = _mm_unpackhi_epi8(bgra0, bgra4);  // b2b6g2g6r2r6a2a6...

    const __m128i v1l = _mm_unpacklo_epi8(v0l, v0h);    // b0b2b4b6g0g2g4g6...

    const __m128i v1h = _mm_unpackhi_epi8(v0l, v0h);    // b1b3b5b7g1g3g5g7...

    const __m128i v2l = _mm_unpacklo_epi8(v1l, v1h);    // b0...b7 | g0...g7

    const __m128i v2h = _mm_unpackhi_epi8(v1l, v1h);    // r0...r7 | a0...a7

    const __m128i ga0 = _mm_unpackhi_epi64(v2l, v2h);   // g0...g7 | a0...a7

    const __m128i rb0 = _mm_unpacklo_epi64(v2h, v2l);   // r0...r7 | b0...b7

    const __m128i ga1 = _mm_srli_epi16(ga0, 4);         // g0-|g1-|...|a6-|a7-

    const __m128i rb1 = _mm_and_si128(rb0, mask_0xf0);  // -r0|-r1|...|-b6|-a7

    const __m128i ga2 = _mm_and_si128(ga1, mask_0x0f);  // g0-|g1-|...|a6-|a7-

    const __m128i rgba0 = _mm_or_si128(ga2, rb1);       // rg0..rg7 | ba0..ba7

    const __m128i rgba1 = _mm_srli_si128(rgba0, 8);     // ba0..ba7 | 0

#if (WEBP_SWAP_16BIT_CSP == 1)

    const __m128i rgba = _mm_unpacklo_epi8(rgba1, rgba0);  // barg0...barg7

#else

    const __m128i rgba = _mm_unpacklo_epi8(rgba0, rgba1);  // rgba0...rgba7

#endif

    _mm_storeu_si128(out++, rgba);

    num_pixels -= 8;

  }

  // left-overs

  if (num_pixels > 0) {

    VP8LConvertBGRAToRGBA4444_C((const uint32_t*)in, num_pixels, (uint8_t*)out);

  }

}

static void ConvertBGRAToRGB565_SSE2(const uint32_t* WEBP_RESTRICT src,

                                     int num_pixels,

                                     uint8_t* WEBP_RESTRICT dst) {

  const __m128i mask_0xe0 = _mm_set1_epi8((char)0xe0);

  const __m128i mask_0xf8 = _mm_set1_epi8((char)0xf8);

  const __m128i mask_0x07 = _mm_set1_epi8(0x07);

  const __m128i* in = (const __m128i*)src;

  __m128i* out = (__m128i*)dst;

  while (num_pixels >= 8) {

    const __m128i bgra0 = _mm_loadu_si128(in++);     // bgra0|bgra1|bgra2|bgra3

    const __m128i bgra4 = _mm_loadu_si128(in++);     // bgra4|bgra5|bgra6|bgra7

    const __m128i v0l = _mm_unpacklo_epi8(bgra0, bgra4);  // b0b4g0g4r0r4a0a4...

    const __m128i v0h = _mm_unpackhi_epi8(bgra0, bgra4);  // b2b6g2g6r2r6a2a6...

    const __m128i v1l = _mm_unpacklo_epi8(v0l, v0h);      // b0b2b4b6g0g2g4g6...

    const __m128i v1h = _mm_unpackhi_epi8(v0l, v0h);      // b1b3b5b7g1g3g5g7...

    const __m128i v2l = _mm_unpacklo_epi8(v1l, v1h);      // b0...b7 | g0...g7

    const __m128i v2h = _mm_unpackhi_epi8(v1l, v1h);      // r0...r7 | a0...a7

    const __m128i ga0 = _mm_unpackhi_epi64(v2l, v2h);     // g0...g7 | a0...a7

    const __m128i rb0 = _mm_unpacklo_epi64(v2h, v2l);     // r0...r7 | b0...b7

    const __m128i rb1 = _mm_and_si128(rb0, mask_0xf8);    // -r0..-r7|-b0..-b7

    const __m128i g_lo1 = _mm_srli_epi16(ga0, 5);

    const __m128i g_lo2 = _mm_and_si128(g_lo1, mask_0x07);  // g0-...g7-|xx (3b)

    const __m128i g_hi1 = _mm_slli_epi16(ga0, 3);

    const __m128i g_hi2 = _mm_and_si128(g_hi1, mask_0xe0);  // -g0...-g7|xx (3b)

    const __m128i b0 = _mm_srli_si128(rb1, 8);              // -b0...-b7|0

    const __m128i rg1 = _mm_or_si128(rb1, g_lo2);           // gr0...gr7|xx

    const __m128i b1 = _mm_srli_epi16(b0, 3);

    const __m128i gb1 = _mm_or_si128(b1, g_hi2);            // bg0...bg7|xx

#if (WEBP_SWAP_16BIT_CSP == 1)

    const __m128i rgba = _mm_unpacklo_epi8(gb1, rg1);     // rggb0...rggb7

#else

    const __m128i rgba = _mm_unpacklo_epi8(rg1, gb1);     // bgrb0...bgrb7

#endif

    _mm_storeu_si128(out++, rgba);

    num_pixels -= 8;

  }

  // left-overs

  if (num_pixels > 0) {

    VP8LConvertBGRAToRGB565_C((const uint32_t*)in, num_pixels, (uint8_t*)out);

  }

}

static void ConvertBGRAToBGR_SSE2(const uint32_t* WEBP_RESTRICT src,

                                  int num_pixels, uint8_t* WEBP_RESTRICT dst) {

  const __m128i mask_l = _mm_set_epi32(0, 0x00ffffff, 0, 0x00ffffff);

  const __m128i mask_h = _mm_set_epi32(0x00ffffff, 0, 0x00ffffff, 0);

  const __m128i* in = (const __m128i*)src;

  const uint8_t* const end = dst + num_pixels * 3;

  // the last storel_epi64 below writes 8 bytes starting at offset 18

  while (dst + 26 <= end) {

    const __m128i bgra0 = _mm_loadu_si128(in++);     // bgra0|bgra1|bgra2|bgra3

    const __m128i bgra4 = _mm_loadu_si128(in++);     // bgra4|bgra5|bgra6|bgra7

    const __m128i a0l = _mm_and_si128(bgra0, mask_l);   // bgr0|0|bgr0|0

    const __m128i a4l = _mm_and_si128(bgra4, mask_l);   // bgr0|0|bgr0|0

    const __m128i a0h = _mm_and_si128(bgra0, mask_h);   // 0|bgr0|0|bgr0

    const __m128i a4h = _mm_and_si128(bgra4, mask_h);   // 0|bgr0|0|bgr0

    const __m128i b0h = _mm_srli_epi64(a0h, 8);         // 000b|gr00|000b|gr00

    const __m128i b4h = _mm_srli_epi64(a4h, 8);         // 000b|gr00|000b|gr00

    const __m128i c0 = _mm_or_si128(a0l, b0h);          // rgbrgb00|rgbrgb00

    const __m128i c4 = _mm_or_si128(a4l, b4h);          // rgbrgb00|rgbrgb00

    const __m128i c2 = _mm_srli_si128(c0, 8);

    const __m128i c6 = _mm_srli_si128(c4, 8);

    _mm_storel_epi64((__m128i*)(dst +   0), c0);

    _mm_storel_epi64((__m128i*)(dst +   6), c2);

    _mm_storel_epi64((__m128i*)(dst +  12), c4);

    _mm_storel_epi64((__m128i*)(dst +  18), c6);

    dst += 24;

    num_pixels -= 8;

  }

  // left-overs

  if (num_pixels > 0) {

    VP8LConvertBGRAToBGR_C((const uint32_t*)in, num_pixels, dst);

  }

}

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

// Entry point

extern void VP8LDspInitSSE2(void);

WEBP_TSAN_IGNORE_FUNCTION void VP8LDspInitSSE2(void) {

  VP8LPredictors[5] = Predictor5_SSE2;

  VP8LPredictors[6] = Predictor6_SSE2;

  VP8LPredictors[7] = Predictor7_SSE2;

  VP8LPredictors[8] = Predictor8_SSE2;

  VP8LPredictors[9] = Predictor9_SSE2;

  VP8LPredictors[10] = Predictor10_SSE2;

  VP8LPredictors[11] = Predictor11_SSE2;

  VP8LPredictors[12] = Predictor12_SSE2;

  VP8LPredictors[13] = Predictor13_SSE2;

  VP8LPredictorsAdd[0] = PredictorAdd0_SSE2;

  VP8LPredictorsAdd[1] = PredictorAdd1_SSE2;

  VP8LPredictorsAdd[2] = PredictorAdd2_SSE2;

  VP8LPredictorsAdd[3] = PredictorAdd3_SSE2;

  VP8LPredictorsAdd[4] = PredictorAdd4_SSE2;

  VP8LPredictorsAdd[5] = PredictorAdd5_SSE2;

  VP8LPredictorsAdd[6] = PredictorAdd6_SSE2;

  VP8LPredictorsAdd[7] = PredictorAdd7_SSE2;

  VP8LPredictorsAdd[8] = PredictorAdd8_SSE2;

  VP8LPredictorsAdd[9] = PredictorAdd9_SSE2;

  VP8LPredictorsAdd[10] = PredictorAdd10_SSE2;

  VP8LPredictorsAdd[11] = PredictorAdd11_SSE2;

  VP8LPredictorsAdd[12] = PredictorAdd12_SSE2;

  VP8LPredictorsAdd[13] = PredictorAdd13_SSE2;

  VP8LAddGreenToBlueAndRed = AddGreenToBlueAndRed_SSE2;

  VP8LTransformColorInverse = TransformColorInverse_SSE2;

  VP8LConvertBGRAToRGB = ConvertBGRAToRGB_SSE2;

  VP8LConvertBGRAToRGBA = ConvertBGRAToRGBA_SSE2;

  VP8LConvertBGRAToRGBA4444 = ConvertBGRAToRGBA4444_SSE2;

  VP8LConvertBGRAToRGB565 = ConvertBGRAToRGB565_SSE2;

  VP8LConvertBGRAToBGR = ConvertBGRAToBGR_SSE2;

  // SSE exports for AVX and above.

  memcpy(VP8LPredictorsAdd_SSE, VP8LPredictorsAdd, sizeof(VP8LPredictorsAdd));

  VP8LAddGreenToBlueAndRed_SSE = AddGreenToBlueAndRed_SSE2;

  VP8LTransformColorInverse_SSE = TransformColorInverse_SSE2;

  VP8LConvertBGRAToRGB_SSE = ConvertBGRAToRGB_SSE2;

  VP8LConvertBGRAToRGBA_SSE = ConvertBGRAToRGBA_SSE2;

}

#else  // !WEBP_USE_SSE2

WEBP_DSP_INIT_STUB(VP8LDspInitSSE2)

#endif  // WEBP_USE_SSE2