summaryrefslogtreecommitdiffstats
path: root/media/libwebp/src/dsp/ssim_sse2.c
blob: 1dcb0eb0ec21f2b26d1cce2088a849031c89d4c6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
// Copyright 2017 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 version of distortion calculation
//
// Author: Skal (pascal.massimino@gmail.com)

#include "src/dsp/dsp.h"

#if defined(WEBP_USE_SSE2)

#include <assert.h>
#include <emmintrin.h>

#include "src/dsp/common_sse2.h"

#if !defined(WEBP_DISABLE_STATS)

// Helper function
static WEBP_INLINE void SubtractAndSquare_SSE2(const __m128i a, const __m128i b,
                                               __m128i* const sum) {
  // take abs(a-b) in 8b
  const __m128i a_b = _mm_subs_epu8(a, b);
  const __m128i b_a = _mm_subs_epu8(b, a);
  const __m128i abs_a_b = _mm_or_si128(a_b, b_a);
  // zero-extend to 16b
  const __m128i zero = _mm_setzero_si128();
  const __m128i C0 = _mm_unpacklo_epi8(abs_a_b, zero);
  const __m128i C1 = _mm_unpackhi_epi8(abs_a_b, zero);
  // multiply with self
  const __m128i sum1 = _mm_madd_epi16(C0, C0);
  const __m128i sum2 = _mm_madd_epi16(C1, C1);
  *sum = _mm_add_epi32(sum1, sum2);
}

//------------------------------------------------------------------------------
// SSIM / PSNR entry point

static uint32_t AccumulateSSE_SSE2(const uint8_t* src1,
                                   const uint8_t* src2, int len) {
  int i = 0;
  uint32_t sse2 = 0;
  if (len >= 16) {
    const int limit = len - 32;
    int32_t tmp[4];
    __m128i sum1;
    __m128i sum = _mm_setzero_si128();
    __m128i a0 = _mm_loadu_si128((const __m128i*)&src1[i]);
    __m128i b0 = _mm_loadu_si128((const __m128i*)&src2[i]);
    i += 16;
    while (i <= limit) {
      const __m128i a1 = _mm_loadu_si128((const __m128i*)&src1[i]);
      const __m128i b1 = _mm_loadu_si128((const __m128i*)&src2[i]);
      __m128i sum2;
      i += 16;
      SubtractAndSquare_SSE2(a0, b0, &sum1);
      sum = _mm_add_epi32(sum, sum1);
      a0 = _mm_loadu_si128((const __m128i*)&src1[i]);
      b0 = _mm_loadu_si128((const __m128i*)&src2[i]);
      i += 16;
      SubtractAndSquare_SSE2(a1, b1, &sum2);
      sum = _mm_add_epi32(sum, sum2);
    }
    SubtractAndSquare_SSE2(a0, b0, &sum1);
    sum = _mm_add_epi32(sum, sum1);
    _mm_storeu_si128((__m128i*)tmp, sum);
    sse2 += (tmp[3] + tmp[2] + tmp[1] + tmp[0]);
  }

  for (; i < len; ++i) {
    const int32_t diff = src1[i] - src2[i];
    sse2 += diff * diff;
  }
  return sse2;
}
#endif  // !defined(WEBP_DISABLE_STATS)

#if !defined(WEBP_REDUCE_SIZE)

static uint32_t HorizontalAdd16b_SSE2(const __m128i* const m) {
  uint16_t tmp[8];
  const __m128i a = _mm_srli_si128(*m, 8);
  const __m128i b = _mm_add_epi16(*m, a);
  _mm_storeu_si128((__m128i*)tmp, b);
  return (uint32_t)tmp[3] + tmp[2] + tmp[1] + tmp[0];
}

static uint32_t HorizontalAdd32b_SSE2(const __m128i* const m) {
  const __m128i a = _mm_srli_si128(*m, 8);
  const __m128i b = _mm_add_epi32(*m, a);
  const __m128i c = _mm_add_epi32(b, _mm_srli_si128(b, 4));
  return (uint32_t)_mm_cvtsi128_si32(c);
}

static const uint16_t kWeight[] = { 1, 2, 3, 4, 3, 2, 1, 0 };

#define ACCUMULATE_ROW(WEIGHT) do {                         \
  /* compute row weight (Wx * Wy) */                        \
  const __m128i Wy = _mm_set1_epi16((WEIGHT));              \
  const __m128i W = _mm_mullo_epi16(Wx, Wy);                \
  /* process 8 bytes at a time (7 bytes, actually) */       \
  const __m128i a0 = _mm_loadl_epi64((const __m128i*)src1); \
  const __m128i b0 = _mm_loadl_epi64((const __m128i*)src2); \
  /* convert to 16b and multiply by weight */               \
  const __m128i a1 = _mm_unpacklo_epi8(a0, zero);           \
  const __m128i b1 = _mm_unpacklo_epi8(b0, zero);           \
  const __m128i wa1 = _mm_mullo_epi16(a1, W);               \
  const __m128i wb1 = _mm_mullo_epi16(b1, W);               \
  /* accumulate */                                          \
  xm  = _mm_add_epi16(xm, wa1);                             \
  ym  = _mm_add_epi16(ym, wb1);                             \
  xxm = _mm_add_epi32(xxm, _mm_madd_epi16(a1, wa1));        \
  xym = _mm_add_epi32(xym, _mm_madd_epi16(a1, wb1));        \
  yym = _mm_add_epi32(yym, _mm_madd_epi16(b1, wb1));        \
  src1 += stride1;                                          \
  src2 += stride2;                                          \
} while (0)

static double SSIMGet_SSE2(const uint8_t* src1, int stride1,
                           const uint8_t* src2, int stride2) {
  VP8DistoStats stats;
  const __m128i zero = _mm_setzero_si128();
  __m128i xm = zero, ym = zero;                // 16b accums
  __m128i xxm = zero, yym = zero, xym = zero;  // 32b accum
  const __m128i Wx = _mm_loadu_si128((const __m128i*)kWeight);
  assert(2 * VP8_SSIM_KERNEL + 1 == 7);
  ACCUMULATE_ROW(1);
  ACCUMULATE_ROW(2);
  ACCUMULATE_ROW(3);
  ACCUMULATE_ROW(4);
  ACCUMULATE_ROW(3);
  ACCUMULATE_ROW(2);
  ACCUMULATE_ROW(1);
  stats.xm  = HorizontalAdd16b_SSE2(&xm);
  stats.ym  = HorizontalAdd16b_SSE2(&ym);
  stats.xxm = HorizontalAdd32b_SSE2(&xxm);
  stats.xym = HorizontalAdd32b_SSE2(&xym);
  stats.yym = HorizontalAdd32b_SSE2(&yym);
  return VP8SSIMFromStats(&stats);
}

#endif  // !defined(WEBP_REDUCE_SIZE)

extern void VP8SSIMDspInitSSE2(void);

WEBP_TSAN_IGNORE_FUNCTION void VP8SSIMDspInitSSE2(void) {
#if !defined(WEBP_DISABLE_STATS)
  VP8AccumulateSSE = AccumulateSSE_SSE2;
#endif
#if !defined(WEBP_REDUCE_SIZE)
  VP8SSIMGet = SSIMGet_SSE2;
#endif
}

#else  // !WEBP_USE_SSE2

WEBP_DSP_INIT_STUB(VP8SSIMDspInitSSE2)

#endif  // WEBP_USE_SSE2