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lossless_sse2.c (31910B)


      1 // Copyright 2014 Google Inc. All Rights Reserved.
      2 //
      3 // Use of this source code is governed by a BSD-style license
      4 // that can be found in the COPYING file in the root of the source
      5 // tree. An additional intellectual property rights grant can be found
      6 // in the file PATENTS. All contributing project authors may
      7 // be found in the AUTHORS file in the root of the source tree.
      8 // -----------------------------------------------------------------------------
      9 //
     10 // SSE2 variant of methods for lossless decoder
     11 //
     12 // Author: Skal (pascal.massimino@gmail.com)
     13 
     14 #include "src/dsp/dsp.h"
     15 
     16 #if defined(WEBP_USE_SSE2)
     17 
     18 #include <emmintrin.h>
     19 #include <string.h>
     20 
     21 #include "src/dsp/common_sse2.h"
     22 #include "src/dsp/cpu.h"
     23 #include "src/dsp/lossless.h"
     24 #include "src/dsp/lossless_common.h"
     25 #include "src/webp/format_constants.h"
     26 #include "src/webp/types.h"
     27 
     28 //------------------------------------------------------------------------------
     29 // Predictor Transform
     30 
     31 static WEBP_INLINE uint32_t ClampedAddSubtractFull_SSE2(uint32_t c0,
     32                                                        uint32_t c1,
     33                                                        uint32_t c2) {
     34  const __m128i zero = _mm_setzero_si128();
     35  const __m128i C0 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c0), zero);
     36  const __m128i C1 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c1), zero);
     37  const __m128i C2 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c2), zero);
     38  const __m128i V1 = _mm_add_epi16(C0, C1);
     39  const __m128i V2 = _mm_sub_epi16(V1, C2);
     40  const __m128i b = _mm_packus_epi16(V2, V2);
     41  return (uint32_t)_mm_cvtsi128_si32(b);
     42 }
     43 
     44 static WEBP_INLINE uint32_t ClampedAddSubtractHalf_SSE2(uint32_t c0,
     45                                                        uint32_t c1,
     46                                                        uint32_t c2) {
     47  const __m128i zero = _mm_setzero_si128();
     48  const __m128i C0 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c0), zero);
     49  const __m128i C1 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c1), zero);
     50  const __m128i B0 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)c2), zero);
     51  const __m128i avg = _mm_add_epi16(C1, C0);
     52  const __m128i A0 = _mm_srli_epi16(avg, 1);
     53  const __m128i A1 = _mm_sub_epi16(A0, B0);
     54  const __m128i BgtA = _mm_cmpgt_epi16(B0, A0);
     55  const __m128i A2 = _mm_sub_epi16(A1, BgtA);
     56  const __m128i A3 = _mm_srai_epi16(A2, 1);
     57  const __m128i A4 = _mm_add_epi16(A0, A3);
     58  const __m128i A5 = _mm_packus_epi16(A4, A4);
     59  return (uint32_t)_mm_cvtsi128_si32(A5);
     60 }
     61 
     62 static WEBP_INLINE uint32_t Select_SSE2(uint32_t a, uint32_t b, uint32_t c) {
     63  int pa_minus_pb;
     64  const __m128i zero = _mm_setzero_si128();
     65  const __m128i A0 = _mm_cvtsi32_si128((int)a);
     66  const __m128i B0 = _mm_cvtsi32_si128((int)b);
     67  const __m128i C0 = _mm_cvtsi32_si128((int)c);
     68  const __m128i AC0 = _mm_subs_epu8(A0, C0);
     69  const __m128i CA0 = _mm_subs_epu8(C0, A0);
     70  const __m128i BC0 = _mm_subs_epu8(B0, C0);
     71  const __m128i CB0 = _mm_subs_epu8(C0, B0);
     72  const __m128i AC = _mm_or_si128(AC0, CA0);
     73  const __m128i BC = _mm_or_si128(BC0, CB0);
     74  const __m128i pa = _mm_unpacklo_epi8(AC, zero);  // |a - c|
     75  const __m128i pb = _mm_unpacklo_epi8(BC, zero);  // |b - c|
     76  const __m128i diff = _mm_sub_epi16(pb, pa);
     77  {
     78    int16_t out[8];
     79    _mm_storeu_si128((__m128i*)out, diff);
     80    pa_minus_pb = out[0] + out[1] + out[2] + out[3];
     81  }
     82  return (pa_minus_pb <= 0) ? a : b;
     83 }
     84 
     85 static WEBP_INLINE void Average2_m128i(const __m128i* const a0,
     86                                       const __m128i* const a1,
     87                                       __m128i* const avg) {
     88  // (a + b) >> 1 = ((a + b + 1) >> 1) - ((a ^ b) & 1)
     89  const __m128i ones = _mm_set1_epi8(1);
     90  const __m128i avg1 = _mm_avg_epu8(*a0, *a1);
     91  const __m128i one = _mm_and_si128(_mm_xor_si128(*a0, *a1), ones);
     92  *avg = _mm_sub_epi8(avg1, one);
     93 }
     94 
     95 static WEBP_INLINE void Average2_uint32_SSE2(const uint32_t a0,
     96                                             const uint32_t a1,
     97                                             __m128i* const avg) {
     98  // (a + b) >> 1 = ((a + b + 1) >> 1) - ((a ^ b) & 1)
     99  const __m128i ones = _mm_set1_epi8(1);
    100  const __m128i A0 = _mm_cvtsi32_si128((int)a0);
    101  const __m128i A1 = _mm_cvtsi32_si128((int)a1);
    102  const __m128i avg1 = _mm_avg_epu8(A0, A1);
    103  const __m128i one = _mm_and_si128(_mm_xor_si128(A0, A1), ones);
    104  *avg = _mm_sub_epi8(avg1, one);
    105 }
    106 
    107 static WEBP_INLINE __m128i Average2_uint32_16_SSE2(uint32_t a0, uint32_t a1) {
    108  const __m128i zero = _mm_setzero_si128();
    109  const __m128i A0 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)a0), zero);
    110  const __m128i A1 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)a1), zero);
    111  const __m128i sum = _mm_add_epi16(A1, A0);
    112  return _mm_srli_epi16(sum, 1);
    113 }
    114 
    115 static WEBP_INLINE uint32_t Average2_SSE2(uint32_t a0, uint32_t a1) {
    116  __m128i output;
    117  Average2_uint32_SSE2(a0, a1, &output);
    118  return (uint32_t)_mm_cvtsi128_si32(output);
    119 }
    120 
    121 static WEBP_INLINE uint32_t Average3_SSE2(uint32_t a0, uint32_t a1,
    122                                          uint32_t a2) {
    123  const __m128i zero = _mm_setzero_si128();
    124  const __m128i avg1 = Average2_uint32_16_SSE2(a0, a2);
    125  const __m128i A1 = _mm_unpacklo_epi8(_mm_cvtsi32_si128((int)a1), zero);
    126  const __m128i sum = _mm_add_epi16(avg1, A1);
    127  const __m128i avg2 = _mm_srli_epi16(sum, 1);
    128  const __m128i A2 = _mm_packus_epi16(avg2, avg2);
    129  return (uint32_t)_mm_cvtsi128_si32(A2);
    130 }
    131 
    132 static WEBP_INLINE uint32_t Average4_SSE2(uint32_t a0, uint32_t a1,
    133                                          uint32_t a2, uint32_t a3) {
    134  const __m128i avg1 = Average2_uint32_16_SSE2(a0, a1);
    135  const __m128i avg2 = Average2_uint32_16_SSE2(a2, a3);
    136  const __m128i sum = _mm_add_epi16(avg2, avg1);
    137  const __m128i avg3 = _mm_srli_epi16(sum, 1);
    138  const __m128i A0 = _mm_packus_epi16(avg3, avg3);
    139  return (uint32_t)_mm_cvtsi128_si32(A0);
    140 }
    141 
    142 static uint32_t Predictor5_SSE2(const uint32_t* const left,
    143                                const uint32_t* const top) {
    144  const uint32_t pred = Average3_SSE2(*left, top[0], top[1]);
    145  return pred;
    146 }
    147 static uint32_t Predictor6_SSE2(const uint32_t* const left,
    148                                const uint32_t* const top) {
    149  const uint32_t pred = Average2_SSE2(*left, top[-1]);
    150  return pred;
    151 }
    152 static uint32_t Predictor7_SSE2(const uint32_t* const left,
    153                                const uint32_t* const top) {
    154  const uint32_t pred = Average2_SSE2(*left, top[0]);
    155  return pred;
    156 }
    157 static uint32_t Predictor8_SSE2(const uint32_t* const left,
    158                                const uint32_t* const top) {
    159  const uint32_t pred = Average2_SSE2(top[-1], top[0]);
    160  (void)left;
    161  return pred;
    162 }
    163 static uint32_t Predictor9_SSE2(const uint32_t* const left,
    164                                const uint32_t* const top) {
    165  const uint32_t pred = Average2_SSE2(top[0], top[1]);
    166  (void)left;
    167  return pred;
    168 }
    169 static uint32_t Predictor10_SSE2(const uint32_t* const left,
    170                                 const uint32_t* const top) {
    171  const uint32_t pred = Average4_SSE2(*left, top[-1], top[0], top[1]);
    172  return pred;
    173 }
    174 static uint32_t Predictor11_SSE2(const uint32_t* const left,
    175                                 const uint32_t* const top) {
    176  const uint32_t pred = Select_SSE2(top[0], *left, top[-1]);
    177  return pred;
    178 }
    179 static uint32_t Predictor12_SSE2(const uint32_t* const left,
    180                                 const uint32_t* const top) {
    181  const uint32_t pred = ClampedAddSubtractFull_SSE2(*left, top[0], top[-1]);
    182  return pred;
    183 }
    184 static uint32_t Predictor13_SSE2(const uint32_t* const left,
    185                                 const uint32_t* const top) {
    186  const uint32_t pred = ClampedAddSubtractHalf_SSE2(*left, top[0], top[-1]);
    187  return pred;
    188 }
    189 
    190 // Batch versions of those functions.
    191 
    192 // Predictor0: ARGB_BLACK.
    193 static void PredictorAdd0_SSE2(const uint32_t* in, const uint32_t* upper,
    194                               int num_pixels, uint32_t* WEBP_RESTRICT out) {
    195  int i;
    196  const __m128i black = _mm_set1_epi32((int)ARGB_BLACK);
    197  for (i = 0; i + 4 <= num_pixels; i += 4) {
    198    const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);
    199    const __m128i res = _mm_add_epi8(src, black);
    200    _mm_storeu_si128((__m128i*)&out[i], res);
    201  }
    202  if (i != num_pixels) {
    203    VP8LPredictorsAdd_C[0](in + i, NULL, num_pixels - i, out + i);
    204  }
    205  (void)upper;
    206 }
    207 
    208 // Predictor1: left.
    209 static void PredictorAdd1_SSE2(const uint32_t* in, const uint32_t* upper,
    210                               int num_pixels, uint32_t* WEBP_RESTRICT out) {
    211  int i;
    212  __m128i prev = _mm_set1_epi32((int)out[-1]);
    213  for (i = 0; i + 4 <= num_pixels; i += 4) {
    214    // a | b | c | d
    215    const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);
    216    // 0 | a | b | c
    217    const __m128i shift0 = _mm_slli_si128(src, 4);
    218    // a | a + b | b + c | c + d
    219    const __m128i sum0 = _mm_add_epi8(src, shift0);
    220    // 0 | 0 | a | a + b
    221    const __m128i shift1 = _mm_slli_si128(sum0, 8);
    222    // a | a + b | a + b + c | a + b + c + d
    223    const __m128i sum1 = _mm_add_epi8(sum0, shift1);
    224    const __m128i res = _mm_add_epi8(sum1, prev);
    225    _mm_storeu_si128((__m128i*)&out[i], res);
    226    // replicate prev output on the four lanes
    227    prev = _mm_shuffle_epi32(res, (3 << 0) | (3 << 2) | (3 << 4) | (3 << 6));
    228  }
    229  if (i != num_pixels) {
    230    VP8LPredictorsAdd_C[1](in + i, upper + i, num_pixels - i, out + i);
    231  }
    232 }
    233 
    234 // Macro that adds 32-bit integers from IN using mod 256 arithmetic
    235 // per 8 bit channel.
    236 #define GENERATE_PREDICTOR_1(X, IN)                                           \
    237 static void PredictorAdd##X##_SSE2(const uint32_t* in, const uint32_t* upper, \
    238                                   int num_pixels,                            \
    239                                   uint32_t* WEBP_RESTRICT out) {             \
    240  int i;                                                                      \
    241  for (i = 0; i + 4 <= num_pixels; i += 4) {                                  \
    242    const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);              \
    243    const __m128i other = _mm_loadu_si128((const __m128i*)&(IN));             \
    244    const __m128i res = _mm_add_epi8(src, other);                             \
    245    _mm_storeu_si128((__m128i*)&out[i], res);                                 \
    246  }                                                                           \
    247  if (i != num_pixels) {                                                      \
    248    VP8LPredictorsAdd_C[(X)](in + i, upper + i, num_pixels - i, out + i);     \
    249  }                                                                           \
    250 }
    251 
    252 // Predictor2: Top.
    253 GENERATE_PREDICTOR_1(2, upper[i])
    254 // Predictor3: Top-right.
    255 GENERATE_PREDICTOR_1(3, upper[i + 1])
    256 // Predictor4: Top-left.
    257 GENERATE_PREDICTOR_1(4, upper[i - 1])
    258 #undef GENERATE_PREDICTOR_1
    259 
    260 // Due to averages with integers, values cannot be accumulated in parallel for
    261 // predictors 5 to 7.
    262 GENERATE_PREDICTOR_ADD(Predictor5_SSE2, PredictorAdd5_SSE2)
    263 GENERATE_PREDICTOR_ADD(Predictor6_SSE2, PredictorAdd6_SSE2)
    264 GENERATE_PREDICTOR_ADD(Predictor7_SSE2, PredictorAdd7_SSE2)
    265 
    266 #define GENERATE_PREDICTOR_2(X, IN)                                           \
    267 static void PredictorAdd##X##_SSE2(const uint32_t* in, const uint32_t* upper, \
    268                                   int num_pixels,                            \
    269                                   uint32_t* WEBP_RESTRICT out) {             \
    270  int i;                                                                      \
    271  for (i = 0; i + 4 <= num_pixels; i += 4) {                                  \
    272    const __m128i Tother = _mm_loadu_si128((const __m128i*)&(IN));            \
    273    const __m128i T = _mm_loadu_si128((const __m128i*)&upper[i]);             \
    274    const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);              \
    275    __m128i avg, res;                                                         \
    276    Average2_m128i(&T, &Tother, &avg);                                        \
    277    res = _mm_add_epi8(avg, src);                                             \
    278    _mm_storeu_si128((__m128i*)&out[i], res);                                 \
    279  }                                                                           \
    280  if (i != num_pixels) {                                                      \
    281    VP8LPredictorsAdd_C[(X)](in + i, upper + i, num_pixels - i, out + i);     \
    282  }                                                                           \
    283 }
    284 // Predictor8: average TL T.
    285 GENERATE_PREDICTOR_2(8, upper[i - 1])
    286 // Predictor9: average T TR.
    287 GENERATE_PREDICTOR_2(9, upper[i + 1])
    288 #undef GENERATE_PREDICTOR_2
    289 
    290 // Predictor10: average of (average of (L,TL), average of (T, TR)).
    291 #define DO_PRED10(OUT) do {                         \
    292  __m128i avgLTL, avg;                              \
    293  Average2_m128i(&L, &TL, &avgLTL);                 \
    294  Average2_m128i(&avgTTR, &avgLTL, &avg);           \
    295  L = _mm_add_epi8(avg, src);                       \
    296  out[i + (OUT)] = (uint32_t)_mm_cvtsi128_si32(L);  \
    297 } while (0)
    298 
    299 #define DO_PRED10_SHIFT do {                                  \
    300  /* Rotate the pre-computed values for the next iteration.*/ \
    301  avgTTR = _mm_srli_si128(avgTTR, 4);                         \
    302  TL = _mm_srli_si128(TL, 4);                                 \
    303  src = _mm_srli_si128(src, 4);                               \
    304 } while (0)
    305 
    306 static void PredictorAdd10_SSE2(const uint32_t* in, const uint32_t* upper,
    307                                int num_pixels, uint32_t* WEBP_RESTRICT out) {
    308  int i;
    309  __m128i L = _mm_cvtsi32_si128((int)out[-1]);
    310  for (i = 0; i + 4 <= num_pixels; i += 4) {
    311    __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);
    312    __m128i TL = _mm_loadu_si128((const __m128i*)&upper[i - 1]);
    313    const __m128i T = _mm_loadu_si128((const __m128i*)&upper[i]);
    314    const __m128i TR = _mm_loadu_si128((const __m128i*)&upper[i + 1]);
    315    __m128i avgTTR;
    316    Average2_m128i(&T, &TR, &avgTTR);
    317    DO_PRED10(0);
    318    DO_PRED10_SHIFT;
    319    DO_PRED10(1);
    320    DO_PRED10_SHIFT;
    321    DO_PRED10(2);
    322    DO_PRED10_SHIFT;
    323    DO_PRED10(3);
    324  }
    325  if (i != num_pixels) {
    326    VP8LPredictorsAdd_C[10](in + i, upper + i, num_pixels - i, out + i);
    327  }
    328 }
    329 #undef DO_PRED10
    330 #undef DO_PRED10_SHIFT
    331 
    332 // Predictor11: select.
    333 #define DO_PRED11(OUT) do {                                            \
    334  const __m128i L_lo = _mm_unpacklo_epi32(L, T);                       \
    335  const __m128i TL_lo = _mm_unpacklo_epi32(TL, T);                     \
    336  const __m128i pb = _mm_sad_epu8(L_lo, TL_lo); /* pb = sum |L-TL|*/   \
    337  const __m128i mask = _mm_cmpgt_epi32(pb, pa);                        \
    338  const __m128i A = _mm_and_si128(mask, L);                            \
    339  const __m128i B = _mm_andnot_si128(mask, T);                         \
    340  const __m128i pred = _mm_or_si128(A, B); /* pred = (pa > b)? L : T*/ \
    341  L = _mm_add_epi8(src, pred);                                         \
    342  out[i + (OUT)] = (uint32_t)_mm_cvtsi128_si32(L);                     \
    343 } while (0)
    344 
    345 #define DO_PRED11_SHIFT do {                                \
    346  /* Shift the pre-computed value for the next iteration.*/ \
    347  T = _mm_srli_si128(T, 4);                                 \
    348  TL = _mm_srli_si128(TL, 4);                               \
    349  src = _mm_srli_si128(src, 4);                             \
    350  pa = _mm_srli_si128(pa, 4);                               \
    351 } while (0)
    352 
    353 static void PredictorAdd11_SSE2(const uint32_t* in, const uint32_t* upper,
    354                                int num_pixels, uint32_t* WEBP_RESTRICT out) {
    355  int i;
    356  __m128i pa;
    357  __m128i L = _mm_cvtsi32_si128((int)out[-1]);
    358  for (i = 0; i + 4 <= num_pixels; i += 4) {
    359    __m128i T = _mm_loadu_si128((const __m128i*)&upper[i]);
    360    __m128i TL = _mm_loadu_si128((const __m128i*)&upper[i - 1]);
    361    __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);
    362    {
    363      // We can unpack with any value on the upper 32 bits, provided it's the
    364      // same on both operands (so that their sum of abs diff is zero). Here we
    365      // use T.
    366      const __m128i T_lo = _mm_unpacklo_epi32(T, T);
    367      const __m128i TL_lo = _mm_unpacklo_epi32(TL, T);
    368      const __m128i T_hi = _mm_unpackhi_epi32(T, T);
    369      const __m128i TL_hi = _mm_unpackhi_epi32(TL, T);
    370      const __m128i s_lo = _mm_sad_epu8(T_lo, TL_lo);
    371      const __m128i s_hi = _mm_sad_epu8(T_hi, TL_hi);
    372      pa = _mm_packs_epi32(s_lo, s_hi);  // pa = sum |T-TL|
    373    }
    374    DO_PRED11(0);
    375    DO_PRED11_SHIFT;
    376    DO_PRED11(1);
    377    DO_PRED11_SHIFT;
    378    DO_PRED11(2);
    379    DO_PRED11_SHIFT;
    380    DO_PRED11(3);
    381  }
    382  if (i != num_pixels) {
    383    VP8LPredictorsAdd_C[11](in + i, upper + i, num_pixels - i, out + i);
    384  }
    385 }
    386 #undef DO_PRED11
    387 #undef DO_PRED11_SHIFT
    388 
    389 // Predictor12: ClampedAddSubtractFull.
    390 #define DO_PRED12(DIFF, LANE, OUT) do {              \
    391  const __m128i all = _mm_add_epi16(L, (DIFF));      \
    392  const __m128i alls = _mm_packus_epi16(all, all);   \
    393  const __m128i res = _mm_add_epi8(src, alls);       \
    394  out[i + (OUT)] = (uint32_t)_mm_cvtsi128_si32(res); \
    395  L = _mm_unpacklo_epi8(res, zero);                  \
    396 } while (0)
    397 
    398 #define DO_PRED12_SHIFT(DIFF, LANE) do {                    \
    399  /* Shift the pre-computed value for the next iteration.*/ \
    400  if ((LANE) == 0) (DIFF) = _mm_srli_si128((DIFF), 8);      \
    401  src = _mm_srli_si128(src, 4);                             \
    402 } while (0)
    403 
    404 static void PredictorAdd12_SSE2(const uint32_t* in, const uint32_t* upper,
    405                                int num_pixels, uint32_t* WEBP_RESTRICT out) {
    406  int i;
    407  const __m128i zero = _mm_setzero_si128();
    408  const __m128i L8 = _mm_cvtsi32_si128((int)out[-1]);
    409  __m128i L = _mm_unpacklo_epi8(L8, zero);
    410  for (i = 0; i + 4 <= num_pixels; i += 4) {
    411    // Load 4 pixels at a time.
    412    __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);
    413    const __m128i T = _mm_loadu_si128((const __m128i*)&upper[i]);
    414    const __m128i T_lo = _mm_unpacklo_epi8(T, zero);
    415    const __m128i T_hi = _mm_unpackhi_epi8(T, zero);
    416    const __m128i TL = _mm_loadu_si128((const __m128i*)&upper[i - 1]);
    417    const __m128i TL_lo = _mm_unpacklo_epi8(TL, zero);
    418    const __m128i TL_hi = _mm_unpackhi_epi8(TL, zero);
    419    __m128i diff_lo = _mm_sub_epi16(T_lo, TL_lo);
    420    __m128i diff_hi = _mm_sub_epi16(T_hi, TL_hi);
    421    DO_PRED12(diff_lo, 0, 0);
    422    DO_PRED12_SHIFT(diff_lo, 0);
    423    DO_PRED12(diff_lo, 1, 1);
    424    DO_PRED12_SHIFT(diff_lo, 1);
    425    DO_PRED12(diff_hi, 0, 2);
    426    DO_PRED12_SHIFT(diff_hi, 0);
    427    DO_PRED12(diff_hi, 1, 3);
    428  }
    429  if (i != num_pixels) {
    430    VP8LPredictorsAdd_C[12](in + i, upper + i, num_pixels - i, out + i);
    431  }
    432 }
    433 #undef DO_PRED12
    434 #undef DO_PRED12_SHIFT
    435 
    436 // Due to averages with integers, values cannot be accumulated in parallel for
    437 // predictors 13.
    438 GENERATE_PREDICTOR_ADD(Predictor13_SSE2, PredictorAdd13_SSE2)
    439 
    440 //------------------------------------------------------------------------------
    441 // Subtract-Green Transform
    442 
    443 static void AddGreenToBlueAndRed_SSE2(const uint32_t* const src, int num_pixels,
    444                                      uint32_t* dst) {
    445  int i;
    446  for (i = 0; i + 4 <= num_pixels; i += 4) {
    447    const __m128i in = _mm_loadu_si128((const __m128i*)&src[i]); // argb
    448    const __m128i A = _mm_srli_epi16(in, 8);     // 0 a 0 g
    449    const __m128i B = _mm_shufflelo_epi16(A, _MM_SHUFFLE(2, 2, 0, 0));
    450    const __m128i C = _mm_shufflehi_epi16(B, _MM_SHUFFLE(2, 2, 0, 0));  // 0g0g
    451    const __m128i out = _mm_add_epi8(in, C);
    452    _mm_storeu_si128((__m128i*)&dst[i], out);
    453  }
    454  // fallthrough and finish off with plain-C
    455  if (i != num_pixels) {
    456    VP8LAddGreenToBlueAndRed_C(src + i, num_pixels - i, dst + i);
    457  }
    458 }
    459 
    460 //------------------------------------------------------------------------------
    461 // Color Transform
    462 
    463 static void TransformColorInverse_SSE2(const VP8LMultipliers* const m,
    464                                       const uint32_t* const src,
    465                                       int num_pixels, uint32_t* dst) {
    466 // sign-extended multiplying constants, pre-shifted by 5.
    467 #define CST(X)  (((int16_t)(m->X << 8)) >> 5)   // sign-extend
    468 #define MK_CST_16(HI, LO) \
    469  _mm_set1_epi32((int)(((uint32_t)(HI) << 16) | ((LO) & 0xffff)))
    470  const __m128i mults_rb = MK_CST_16(CST(green_to_red), CST(green_to_blue));
    471  const __m128i mults_b2 = MK_CST_16(CST(red_to_blue), 0);
    472 #undef MK_CST_16
    473 #undef CST
    474  const __m128i mask_ag = _mm_set1_epi32((int)0xff00ff00);  // alpha-green masks
    475  int i;
    476  for (i = 0; i + 4 <= num_pixels; i += 4) {
    477    const __m128i in = _mm_loadu_si128((const __m128i*)&src[i]); // argb
    478    const __m128i A = _mm_and_si128(in, mask_ag);     // a   0   g   0
    479    const __m128i B = _mm_shufflelo_epi16(A, _MM_SHUFFLE(2, 2, 0, 0));
    480    const __m128i C = _mm_shufflehi_epi16(B, _MM_SHUFFLE(2, 2, 0, 0));  // g0g0
    481    const __m128i D = _mm_mulhi_epi16(C, mults_rb);    // x dr  x db1
    482    const __m128i E = _mm_add_epi8(in, D);             // x r'  x   b'
    483    const __m128i F = _mm_slli_epi16(E, 8);            // r' 0   b' 0
    484    const __m128i G = _mm_mulhi_epi16(F, mults_b2);    // x db2  0  0
    485    const __m128i H = _mm_srli_epi32(G, 8);            // 0  x db2  0
    486    const __m128i I = _mm_add_epi8(H, F);              // r' x  b'' 0
    487    const __m128i J = _mm_srli_epi16(I, 8);            // 0  r'  0  b''
    488    const __m128i out = _mm_or_si128(J, A);
    489    _mm_storeu_si128((__m128i*)&dst[i], out);
    490  }
    491  // Fall-back to C-version for left-overs.
    492  if (i != num_pixels) {
    493    VP8LTransformColorInverse_C(m, src + i, num_pixels - i, dst + i);
    494  }
    495 }
    496 
    497 //------------------------------------------------------------------------------
    498 // Color-space conversion functions
    499 
    500 static void ConvertBGRAToRGB_SSE2(const uint32_t* WEBP_RESTRICT src,
    501                                  int num_pixels, uint8_t* WEBP_RESTRICT dst) {
    502  const __m128i* in = (const __m128i*)src;
    503  __m128i* out = (__m128i*)dst;
    504 
    505  while (num_pixels >= 32) {
    506    // Load the BGRA buffers.
    507    __m128i in0 = _mm_loadu_si128(in + 0);
    508    __m128i in1 = _mm_loadu_si128(in + 1);
    509    __m128i in2 = _mm_loadu_si128(in + 2);
    510    __m128i in3 = _mm_loadu_si128(in + 3);
    511    __m128i in4 = _mm_loadu_si128(in + 4);
    512    __m128i in5 = _mm_loadu_si128(in + 5);
    513    __m128i in6 = _mm_loadu_si128(in + 6);
    514    __m128i in7 = _mm_loadu_si128(in + 7);
    515    VP8L32bToPlanar_SSE2(&in0, &in1, &in2, &in3);
    516    VP8L32bToPlanar_SSE2(&in4, &in5, &in6, &in7);
    517    // At this points, in1/in5 contains red only, in2/in6 green only ...
    518    // Pack the colors in 24b RGB.
    519    VP8PlanarTo24b_SSE2(&in1, &in5, &in2, &in6, &in3, &in7);
    520    _mm_storeu_si128(out + 0, in1);
    521    _mm_storeu_si128(out + 1, in5);
    522    _mm_storeu_si128(out + 2, in2);
    523    _mm_storeu_si128(out + 3, in6);
    524    _mm_storeu_si128(out + 4, in3);
    525    _mm_storeu_si128(out + 5, in7);
    526    in += 8;
    527    out += 6;
    528    num_pixels -= 32;
    529  }
    530  // left-overs
    531  if (num_pixels > 0) {
    532    VP8LConvertBGRAToRGB_C((const uint32_t*)in, num_pixels, (uint8_t*)out);
    533  }
    534 }
    535 
    536 static void ConvertBGRAToRGBA_SSE2(const uint32_t* WEBP_RESTRICT src,
    537                                   int num_pixels, uint8_t* WEBP_RESTRICT dst) {
    538  const __m128i red_blue_mask = _mm_set1_epi32(0x00ff00ff);
    539  const __m128i* in = (const __m128i*)src;
    540  __m128i* out = (__m128i*)dst;
    541  while (num_pixels >= 8) {
    542    const __m128i A1 = _mm_loadu_si128(in++);
    543    const __m128i A2 = _mm_loadu_si128(in++);
    544    const __m128i B1 = _mm_and_si128(A1, red_blue_mask);     // R 0 B 0
    545    const __m128i B2 = _mm_and_si128(A2, red_blue_mask);     // R 0 B 0
    546    const __m128i C1 = _mm_andnot_si128(red_blue_mask, A1);  // 0 G 0 A
    547    const __m128i C2 = _mm_andnot_si128(red_blue_mask, A2);  // 0 G 0 A
    548    const __m128i D1 = _mm_shufflelo_epi16(B1, _MM_SHUFFLE(2, 3, 0, 1));
    549    const __m128i D2 = _mm_shufflelo_epi16(B2, _MM_SHUFFLE(2, 3, 0, 1));
    550    const __m128i E1 = _mm_shufflehi_epi16(D1, _MM_SHUFFLE(2, 3, 0, 1));
    551    const __m128i E2 = _mm_shufflehi_epi16(D2, _MM_SHUFFLE(2, 3, 0, 1));
    552    const __m128i F1 = _mm_or_si128(E1, C1);
    553    const __m128i F2 = _mm_or_si128(E2, C2);
    554    _mm_storeu_si128(out++, F1);
    555    _mm_storeu_si128(out++, F2);
    556    num_pixels -= 8;
    557  }
    558  // left-overs
    559  if (num_pixels > 0) {
    560    VP8LConvertBGRAToRGBA_C((const uint32_t*)in, num_pixels, (uint8_t*)out);
    561  }
    562 }
    563 
    564 static void ConvertBGRAToRGBA4444_SSE2(const uint32_t* WEBP_RESTRICT src,
    565                                       int num_pixels,
    566                                       uint8_t* WEBP_RESTRICT dst) {
    567  const __m128i mask_0x0f = _mm_set1_epi8(0x0f);
    568  const __m128i mask_0xf0 = _mm_set1_epi8((char)0xf0);
    569  const __m128i* in = (const __m128i*)src;
    570  __m128i* out = (__m128i*)dst;
    571  while (num_pixels >= 8) {
    572    const __m128i bgra0 = _mm_loadu_si128(in++);     // bgra0|bgra1|bgra2|bgra3
    573    const __m128i bgra4 = _mm_loadu_si128(in++);     // bgra4|bgra5|bgra6|bgra7
    574    const __m128i v0l = _mm_unpacklo_epi8(bgra0, bgra4);  // b0b4g0g4r0r4a0a4...
    575    const __m128i v0h = _mm_unpackhi_epi8(bgra0, bgra4);  // b2b6g2g6r2r6a2a6...
    576    const __m128i v1l = _mm_unpacklo_epi8(v0l, v0h);    // b0b2b4b6g0g2g4g6...
    577    const __m128i v1h = _mm_unpackhi_epi8(v0l, v0h);    // b1b3b5b7g1g3g5g7...
    578    const __m128i v2l = _mm_unpacklo_epi8(v1l, v1h);    // b0...b7 | g0...g7
    579    const __m128i v2h = _mm_unpackhi_epi8(v1l, v1h);    // r0...r7 | a0...a7
    580    const __m128i ga0 = _mm_unpackhi_epi64(v2l, v2h);   // g0...g7 | a0...a7
    581    const __m128i rb0 = _mm_unpacklo_epi64(v2h, v2l);   // r0...r7 | b0...b7
    582    const __m128i ga1 = _mm_srli_epi16(ga0, 4);         // g0-|g1-|...|a6-|a7-
    583    const __m128i rb1 = _mm_and_si128(rb0, mask_0xf0);  // -r0|-r1|...|-b6|-a7
    584    const __m128i ga2 = _mm_and_si128(ga1, mask_0x0f);  // g0-|g1-|...|a6-|a7-
    585    const __m128i rgba0 = _mm_or_si128(ga2, rb1);       // rg0..rg7 | ba0..ba7
    586    const __m128i rgba1 = _mm_srli_si128(rgba0, 8);     // ba0..ba7 | 0
    587 #if (WEBP_SWAP_16BIT_CSP == 1)
    588    const __m128i rgba = _mm_unpacklo_epi8(rgba1, rgba0);  // barg0...barg7
    589 #else
    590    const __m128i rgba = _mm_unpacklo_epi8(rgba0, rgba1);  // rgba0...rgba7
    591 #endif
    592    _mm_storeu_si128(out++, rgba);
    593    num_pixels -= 8;
    594  }
    595  // left-overs
    596  if (num_pixels > 0) {
    597    VP8LConvertBGRAToRGBA4444_C((const uint32_t*)in, num_pixels, (uint8_t*)out);
    598  }
    599 }
    600 
    601 static void ConvertBGRAToRGB565_SSE2(const uint32_t* WEBP_RESTRICT src,
    602                                     int num_pixels,
    603                                     uint8_t* WEBP_RESTRICT dst) {
    604  const __m128i mask_0xe0 = _mm_set1_epi8((char)0xe0);
    605  const __m128i mask_0xf8 = _mm_set1_epi8((char)0xf8);
    606  const __m128i mask_0x07 = _mm_set1_epi8(0x07);
    607  const __m128i* in = (const __m128i*)src;
    608  __m128i* out = (__m128i*)dst;
    609  while (num_pixels >= 8) {
    610    const __m128i bgra0 = _mm_loadu_si128(in++);     // bgra0|bgra1|bgra2|bgra3
    611    const __m128i bgra4 = _mm_loadu_si128(in++);     // bgra4|bgra5|bgra6|bgra7
    612    const __m128i v0l = _mm_unpacklo_epi8(bgra0, bgra4);  // b0b4g0g4r0r4a0a4...
    613    const __m128i v0h = _mm_unpackhi_epi8(bgra0, bgra4);  // b2b6g2g6r2r6a2a6...
    614    const __m128i v1l = _mm_unpacklo_epi8(v0l, v0h);      // b0b2b4b6g0g2g4g6...
    615    const __m128i v1h = _mm_unpackhi_epi8(v0l, v0h);      // b1b3b5b7g1g3g5g7...
    616    const __m128i v2l = _mm_unpacklo_epi8(v1l, v1h);      // b0...b7 | g0...g7
    617    const __m128i v2h = _mm_unpackhi_epi8(v1l, v1h);      // r0...r7 | a0...a7
    618    const __m128i ga0 = _mm_unpackhi_epi64(v2l, v2h);     // g0...g7 | a0...a7
    619    const __m128i rb0 = _mm_unpacklo_epi64(v2h, v2l);     // r0...r7 | b0...b7
    620    const __m128i rb1 = _mm_and_si128(rb0, mask_0xf8);    // -r0..-r7|-b0..-b7
    621    const __m128i g_lo1 = _mm_srli_epi16(ga0, 5);
    622    const __m128i g_lo2 = _mm_and_si128(g_lo1, mask_0x07);  // g0-...g7-|xx (3b)
    623    const __m128i g_hi1 = _mm_slli_epi16(ga0, 3);
    624    const __m128i g_hi2 = _mm_and_si128(g_hi1, mask_0xe0);  // -g0...-g7|xx (3b)
    625    const __m128i b0 = _mm_srli_si128(rb1, 8);              // -b0...-b7|0
    626    const __m128i rg1 = _mm_or_si128(rb1, g_lo2);           // gr0...gr7|xx
    627    const __m128i b1 = _mm_srli_epi16(b0, 3);
    628    const __m128i gb1 = _mm_or_si128(b1, g_hi2);            // bg0...bg7|xx
    629 #if (WEBP_SWAP_16BIT_CSP == 1)
    630    const __m128i rgba = _mm_unpacklo_epi8(gb1, rg1);     // rggb0...rggb7
    631 #else
    632    const __m128i rgba = _mm_unpacklo_epi8(rg1, gb1);     // bgrb0...bgrb7
    633 #endif
    634    _mm_storeu_si128(out++, rgba);
    635    num_pixels -= 8;
    636  }
    637  // left-overs
    638  if (num_pixels > 0) {
    639    VP8LConvertBGRAToRGB565_C((const uint32_t*)in, num_pixels, (uint8_t*)out);
    640  }
    641 }
    642 
    643 static void ConvertBGRAToBGR_SSE2(const uint32_t* WEBP_RESTRICT src,
    644                                  int num_pixels, uint8_t* WEBP_RESTRICT dst) {
    645  const __m128i mask_l = _mm_set_epi32(0, 0x00ffffff, 0, 0x00ffffff);
    646  const __m128i mask_h = _mm_set_epi32(0x00ffffff, 0, 0x00ffffff, 0);
    647  const __m128i* in = (const __m128i*)src;
    648  const uint8_t* const end = dst + num_pixels * 3;
    649  // the last storel_epi64 below writes 8 bytes starting at offset 18
    650  while (dst + 26 <= end) {
    651    const __m128i bgra0 = _mm_loadu_si128(in++);     // bgra0|bgra1|bgra2|bgra3
    652    const __m128i bgra4 = _mm_loadu_si128(in++);     // bgra4|bgra5|bgra6|bgra7
    653    const __m128i a0l = _mm_and_si128(bgra0, mask_l);   // bgr0|0|bgr0|0
    654    const __m128i a4l = _mm_and_si128(bgra4, mask_l);   // bgr0|0|bgr0|0
    655    const __m128i a0h = _mm_and_si128(bgra0, mask_h);   // 0|bgr0|0|bgr0
    656    const __m128i a4h = _mm_and_si128(bgra4, mask_h);   // 0|bgr0|0|bgr0
    657    const __m128i b0h = _mm_srli_epi64(a0h, 8);         // 000b|gr00|000b|gr00
    658    const __m128i b4h = _mm_srli_epi64(a4h, 8);         // 000b|gr00|000b|gr00
    659    const __m128i c0 = _mm_or_si128(a0l, b0h);          // rgbrgb00|rgbrgb00
    660    const __m128i c4 = _mm_or_si128(a4l, b4h);          // rgbrgb00|rgbrgb00
    661    const __m128i c2 = _mm_srli_si128(c0, 8);
    662    const __m128i c6 = _mm_srli_si128(c4, 8);
    663    _mm_storel_epi64((__m128i*)(dst +   0), c0);
    664    _mm_storel_epi64((__m128i*)(dst +   6), c2);
    665    _mm_storel_epi64((__m128i*)(dst +  12), c4);
    666    _mm_storel_epi64((__m128i*)(dst +  18), c6);
    667    dst += 24;
    668    num_pixels -= 8;
    669  }
    670  // left-overs
    671  if (num_pixels > 0) {
    672    VP8LConvertBGRAToBGR_C((const uint32_t*)in, num_pixels, dst);
    673  }
    674 }
    675 
    676 //------------------------------------------------------------------------------
    677 // Entry point
    678 
    679 extern void VP8LDspInitSSE2(void);
    680 
    681 WEBP_TSAN_IGNORE_FUNCTION void VP8LDspInitSSE2(void) {
    682  VP8LPredictors[5] = Predictor5_SSE2;
    683  VP8LPredictors[6] = Predictor6_SSE2;
    684  VP8LPredictors[7] = Predictor7_SSE2;
    685  VP8LPredictors[8] = Predictor8_SSE2;
    686  VP8LPredictors[9] = Predictor9_SSE2;
    687  VP8LPredictors[10] = Predictor10_SSE2;
    688  VP8LPredictors[11] = Predictor11_SSE2;
    689  VP8LPredictors[12] = Predictor12_SSE2;
    690  VP8LPredictors[13] = Predictor13_SSE2;
    691 
    692  VP8LPredictorsAdd[0] = PredictorAdd0_SSE2;
    693  VP8LPredictorsAdd[1] = PredictorAdd1_SSE2;
    694  VP8LPredictorsAdd[2] = PredictorAdd2_SSE2;
    695  VP8LPredictorsAdd[3] = PredictorAdd3_SSE2;
    696  VP8LPredictorsAdd[4] = PredictorAdd4_SSE2;
    697  VP8LPredictorsAdd[5] = PredictorAdd5_SSE2;
    698  VP8LPredictorsAdd[6] = PredictorAdd6_SSE2;
    699  VP8LPredictorsAdd[7] = PredictorAdd7_SSE2;
    700  VP8LPredictorsAdd[8] = PredictorAdd8_SSE2;
    701  VP8LPredictorsAdd[9] = PredictorAdd9_SSE2;
    702  VP8LPredictorsAdd[10] = PredictorAdd10_SSE2;
    703  VP8LPredictorsAdd[11] = PredictorAdd11_SSE2;
    704  VP8LPredictorsAdd[12] = PredictorAdd12_SSE2;
    705  VP8LPredictorsAdd[13] = PredictorAdd13_SSE2;
    706 
    707  VP8LAddGreenToBlueAndRed = AddGreenToBlueAndRed_SSE2;
    708  VP8LTransformColorInverse = TransformColorInverse_SSE2;
    709 
    710  VP8LConvertBGRAToRGB = ConvertBGRAToRGB_SSE2;
    711  VP8LConvertBGRAToRGBA = ConvertBGRAToRGBA_SSE2;
    712  VP8LConvertBGRAToRGBA4444 = ConvertBGRAToRGBA4444_SSE2;
    713  VP8LConvertBGRAToRGB565 = ConvertBGRAToRGB565_SSE2;
    714  VP8LConvertBGRAToBGR = ConvertBGRAToBGR_SSE2;
    715 
    716  // SSE exports for AVX and above.
    717  memcpy(VP8LPredictorsAdd_SSE, VP8LPredictorsAdd, sizeof(VP8LPredictorsAdd));
    718 
    719  VP8LAddGreenToBlueAndRed_SSE = AddGreenToBlueAndRed_SSE2;
    720  VP8LTransformColorInverse_SSE = TransformColorInverse_SSE2;
    721 
    722  VP8LConvertBGRAToRGB_SSE = ConvertBGRAToRGB_SSE2;
    723  VP8LConvertBGRAToRGBA_SSE = ConvertBGRAToRGBA_SSE2;
    724 }
    725 
    726 #else  // !WEBP_USE_SSE2
    727 
    728 WEBP_DSP_INIT_STUB(VP8LDspInitSSE2)
    729 
    730 #endif  // WEBP_USE_SSE2