aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/libwebp/dsp/alpha_processing_sse2.c
blob: a3de73d449838ebd9060768f6dc9a4eb3f118cd5 (plain) (blame)
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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
// 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.
// -----------------------------------------------------------------------------
//
// Utilities for processing transparent channel.
//
// Author: Skal (pascal.massimino@gmail.com)

#include "./dsp.h"

#if defined(WEBP_USE_SSE2)
#include <emmintrin.h>

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

static int DispatchAlpha_SSE2(const uint8_t* WEBP_RESTRICT alpha,
                              int alpha_stride, int width, int height,
                              uint8_t* WEBP_RESTRICT dst, int dst_stride) {
  // alpha_and stores an 'and' operation of all the alpha[] values. The final
  // value is not 0xff if any of the alpha[] is not equal to 0xff.
  uint32_t alpha_and = 0xff;
  int i, j;
  const __m128i zero = _mm_setzero_si128();
  const __m128i rgb_mask = _mm_set1_epi32(0xffffff00u);  // to preserve RGB
  const __m128i all_0xff = _mm_set_epi32(0, 0, ~0u, ~0u);
  __m128i all_alphas = all_0xff;

  // We must be able to access 3 extra bytes after the last written byte
  // 'dst[4 * width - 4]', because we don't know if alpha is the first or the
  // last byte of the quadruplet.
  const int limit = (width - 1) & ~7;

  for (j = 0; j < height; ++j) {
    __m128i* out = (__m128i*)dst;
    for (i = 0; i < limit; i += 8) {
      // load 8 alpha bytes
      const __m128i a0 = _mm_loadl_epi64((const __m128i*)&alpha[i]);
      const __m128i a1 = _mm_unpacklo_epi8(a0, zero);
      const __m128i a2_lo = _mm_unpacklo_epi16(a1, zero);
      const __m128i a2_hi = _mm_unpackhi_epi16(a1, zero);
      // load 8 dst pixels (32 bytes)
      const __m128i b0_lo = _mm_loadu_si128(out + 0);
      const __m128i b0_hi = _mm_loadu_si128(out + 1);
      // mask dst alpha values
      const __m128i b1_lo = _mm_and_si128(b0_lo, rgb_mask);
      const __m128i b1_hi = _mm_and_si128(b0_hi, rgb_mask);
      // combine
      const __m128i b2_lo = _mm_or_si128(b1_lo, a2_lo);
      const __m128i b2_hi = _mm_or_si128(b1_hi, a2_hi);
      // store
      _mm_storeu_si128(out + 0, b2_lo);
      _mm_storeu_si128(out + 1, b2_hi);
      // accumulate eight alpha 'and' in parallel
      all_alphas = _mm_and_si128(all_alphas, a0);
      out += 2;
    }
    for (; i < width; ++i) {
      const uint32_t alpha_value = alpha[i];
      dst[4 * i] = alpha_value;
      alpha_and &= alpha_value;
    }
    alpha += alpha_stride;
    dst += dst_stride;
  }
  // Combine the eight alpha 'and' into a 8-bit mask.
  alpha_and &= _mm_movemask_epi8(_mm_cmpeq_epi8(all_alphas, all_0xff));
  return (alpha_and != 0xff);
}

static void DispatchAlphaToGreen_SSE2(const uint8_t* WEBP_RESTRICT alpha,
                                      int alpha_stride, int width, int height,
                                      uint32_t* WEBP_RESTRICT dst,
                                      int dst_stride) {
  int i, j;
  const __m128i zero = _mm_setzero_si128();
  const int limit = width & ~15;
  for (j = 0; j < height; ++j) {
    for (i = 0; i < limit; i += 16) {   // process 16 alpha bytes
      const __m128i a0 = _mm_loadu_si128((const __m128i*)&alpha[i]);
      const __m128i a1 = _mm_unpacklo_epi8(zero, a0);  // note the 'zero' first!
      const __m128i b1 = _mm_unpackhi_epi8(zero, a0);
      const __m128i a2_lo = _mm_unpacklo_epi16(a1, zero);
      const __m128i b2_lo = _mm_unpacklo_epi16(b1, zero);
      const __m128i a2_hi = _mm_unpackhi_epi16(a1, zero);
      const __m128i b2_hi = _mm_unpackhi_epi16(b1, zero);
      _mm_storeu_si128((__m128i*)&dst[i +  0], a2_lo);
      _mm_storeu_si128((__m128i*)&dst[i +  4], a2_hi);
      _mm_storeu_si128((__m128i*)&dst[i +  8], b2_lo);
      _mm_storeu_si128((__m128i*)&dst[i + 12], b2_hi);
    }
    for (; i < width; ++i) dst[i] = alpha[i] << 8;
    alpha += alpha_stride;
    dst += dst_stride;
  }
}

static int ExtractAlpha_SSE2(const uint8_t* WEBP_RESTRICT argb, int argb_stride,
                             int width, int height,
                             uint8_t* WEBP_RESTRICT alpha, int alpha_stride) {
  // alpha_and stores an 'and' operation of all the alpha[] values. The final
  // value is not 0xff if any of the alpha[] is not equal to 0xff.
  uint32_t alpha_and = 0xff;
  int i, j;
  const __m128i a_mask = _mm_set1_epi32(0xffu);  // to preserve alpha
  const __m128i all_0xff = _mm_set_epi32(0, 0, ~0u, ~0u);
  __m128i all_alphas = all_0xff;

  // We must be able to access 3 extra bytes after the last written byte
  // 'src[4 * width - 4]', because we don't know if alpha is the first or the
  // last byte of the quadruplet.
  const int limit = (width - 1) & ~7;

  for (j = 0; j < height; ++j) {
    const __m128i* src = (const __m128i*)argb;
    for (i = 0; i < limit; i += 8) {
      // load 32 argb bytes
      const __m128i a0 = _mm_loadu_si128(src + 0);
      const __m128i a1 = _mm_loadu_si128(src + 1);
      const __m128i b0 = _mm_and_si128(a0, a_mask);
      const __m128i b1 = _mm_and_si128(a1, a_mask);
      const __m128i c0 = _mm_packs_epi32(b0, b1);
      const __m128i d0 = _mm_packus_epi16(c0, c0);
      // store
      _mm_storel_epi64((__m128i*)&alpha[i], d0);
      // accumulate eight alpha 'and' in parallel
      all_alphas = _mm_and_si128(all_alphas, d0);
      src += 2;
    }
    for (; i < width; ++i) {
      const uint32_t alpha_value = argb[4 * i];
      alpha[i] = alpha_value;
      alpha_and &= alpha_value;
    }
    argb += argb_stride;
    alpha += alpha_stride;
  }
  // Combine the eight alpha 'and' into a 8-bit mask.
  alpha_and &= _mm_movemask_epi8(_mm_cmpeq_epi8(all_alphas, all_0xff));
  return (alpha_and == 0xff);
}

//------------------------------------------------------------------------------
// Non-dither premultiplied modes

#define MULTIPLIER(a)   ((a) * 0x8081)
#define PREMULTIPLY(x, m) (((x) * (m)) >> 23)

// We can't use a 'const int' for the SHUFFLE value, because it has to be an
// immediate in the _mm_shufflexx_epi16() instruction. We really need a macro.
// We use: v / 255 = (v * 0x8081) >> 23, where v = alpha * {r,g,b} is a 16bit
// value.
#define APPLY_ALPHA(RGBX, SHUFFLE) do {                              \
  const __m128i argb0 = _mm_loadu_si128((const __m128i*)&(RGBX));    \
  const __m128i argb1_lo = _mm_unpacklo_epi8(argb0, zero);           \
  const __m128i argb1_hi = _mm_unpackhi_epi8(argb0, zero);           \
  const __m128i alpha0_lo = _mm_or_si128(argb1_lo, kMask);           \
  const __m128i alpha0_hi = _mm_or_si128(argb1_hi, kMask);           \
  const __m128i alpha1_lo = _mm_shufflelo_epi16(alpha0_lo, SHUFFLE); \
  const __m128i alpha1_hi = _mm_shufflelo_epi16(alpha0_hi, SHUFFLE); \
  const __m128i alpha2_lo = _mm_shufflehi_epi16(alpha1_lo, SHUFFLE); \
  const __m128i alpha2_hi = _mm_shufflehi_epi16(alpha1_hi, SHUFFLE); \
  /* alpha2 = [ff a0 a0 a0][ff a1 a1 a1] */                          \
  const __m128i A0_lo = _mm_mullo_epi16(alpha2_lo, argb1_lo);        \
  const __m128i A0_hi = _mm_mullo_epi16(alpha2_hi, argb1_hi);        \
  const __m128i A1_lo = _mm_mulhi_epu16(A0_lo, kMult);               \
  const __m128i A1_hi = _mm_mulhi_epu16(A0_hi, kMult);               \
  const __m128i A2_lo = _mm_srli_epi16(A1_lo, 7);                    \
  const __m128i A2_hi = _mm_srli_epi16(A1_hi, 7);                    \
  const __m128i A3 = _mm_packus_epi16(A2_lo, A2_hi);                 \
  _mm_storeu_si128((__m128i*)&(RGBX), A3);                           \
} while (0)

static void ApplyAlphaMultiply_SSE2(uint8_t* rgba, int alpha_first,
                                    int w, int h, int stride) {
  const __m128i zero = _mm_setzero_si128();
  const __m128i kMult = _mm_set1_epi16(0x8081u);
  const __m128i kMask = _mm_set_epi16(0, 0xff, 0xff, 0, 0, 0xff, 0xff, 0);
  const int kSpan = 4;
  while (h-- > 0) {
    uint32_t* const rgbx = (uint32_t*)rgba;
    int i;
    if (!alpha_first) {
      for (i = 0; i + kSpan <= w; i += kSpan) {
        APPLY_ALPHA(rgbx[i], _MM_SHUFFLE(2, 3, 3, 3));
      }
    } else {
      for (i = 0; i + kSpan <= w; i += kSpan) {
        APPLY_ALPHA(rgbx[i], _MM_SHUFFLE(0, 0, 0, 1));
      }
    }
    // Finish with left-overs.
    for (; i < w; ++i) {
      uint8_t* const rgb = rgba + (alpha_first ? 1 : 0);
      const uint8_t* const alpha = rgba + (alpha_first ? 0 : 3);
      const uint32_t a = alpha[4 * i];
      if (a != 0xff) {
        const uint32_t mult = MULTIPLIER(a);
        rgb[4 * i + 0] = PREMULTIPLY(rgb[4 * i + 0], mult);
        rgb[4 * i + 1] = PREMULTIPLY(rgb[4 * i + 1], mult);
        rgb[4 * i + 2] = PREMULTIPLY(rgb[4 * i + 2], mult);
      }
    }
    rgba += stride;
  }
}
#undef MULTIPLIER
#undef PREMULTIPLY

//------------------------------------------------------------------------------
// Alpha detection

static int HasAlpha8b_SSE2(const uint8_t* src, int length) {
  const __m128i all_0xff = _mm_set1_epi8((char)0xff);
  int i = 0;
  for (; i + 16 <= length; i += 16) {
    const __m128i v = _mm_loadu_si128((const __m128i*)(src + i));
    const __m128i bits = _mm_cmpeq_epi8(v, all_0xff);
    const int mask = _mm_movemask_epi8(bits);
    if (mask != 0xffff) return 1;
  }
  for (; i < length; ++i) if (src[i] != 0xff) return 1;
  return 0;
}

static int HasAlpha32b_SSE2(const uint8_t* src, int length) {
  const __m128i alpha_mask = _mm_set1_epi32(0xff);
  const __m128i all_0xff = _mm_set1_epi8((char)0xff);
  int i = 0;
  // We don't know if we can access the last 3 bytes after the last alpha
  // value 'src[4 * length - 4]' (because we don't know if alpha is the first
  // or the last byte of the quadruplet). Hence the '-3' protection below.
  length = length * 4 - 3;   // size in bytes
  for (; i + 64 <= length; i += 64) {
    const __m128i a0 = _mm_loadu_si128((const __m128i*)(src + i +  0));
    const __m128i a1 = _mm_loadu_si128((const __m128i*)(src + i + 16));
    const __m128i a2 = _mm_loadu_si128((const __m128i*)(src + i + 32));
    const __m128i a3 = _mm_loadu_si128((const __m128i*)(src + i + 48));
    const __m128i b0 = _mm_and_si128(a0, alpha_mask);
    const __m128i b1 = _mm_and_si128(a1, alpha_mask);
    const __m128i b2 = _mm_and_si128(a2, alpha_mask);
    const __m128i b3 = _mm_and_si128(a3, alpha_mask);
    const __m128i c0 = _mm_packs_epi32(b0, b1);
    const __m128i c1 = _mm_packs_epi32(b2, b3);
    const __m128i d  = _mm_packus_epi16(c0, c1);
    const __m128i bits = _mm_cmpeq_epi8(d, all_0xff);
    const int mask = _mm_movemask_epi8(bits);
    if (mask != 0xffff) return 1;
  }
  for (; i + 32 <= length; i += 32) {
    const __m128i a0 = _mm_loadu_si128((const __m128i*)(src + i +  0));
    const __m128i a1 = _mm_loadu_si128((const __m128i*)(src + i + 16));
    const __m128i b0 = _mm_and_si128(a0, alpha_mask);
    const __m128i b1 = _mm_and_si128(a1, alpha_mask);
    const __m128i c  = _mm_packs_epi32(b0, b1);
    const __m128i d  = _mm_packus_epi16(c, c);
    const __m128i bits = _mm_cmpeq_epi8(d, all_0xff);
    const int mask = _mm_movemask_epi8(bits);
    if (mask != 0xffff) return 1;
  }
  for (; i <= length; i += 4) if (src[i] != 0xff) return 1;
  return 0;
}

static void AlphaReplace_SSE2(uint32_t* src, int length, uint32_t color) {
  const __m128i m_color = _mm_set1_epi32(color);
  const __m128i zero = _mm_setzero_si128();
  int i = 0;
  for (; i + 8 <= length; i += 8) {
    const __m128i a0 = _mm_loadu_si128((const __m128i*)(src + i + 0));
    const __m128i a1 = _mm_loadu_si128((const __m128i*)(src + i + 4));
    const __m128i b0 = _mm_srai_epi32(a0, 24);
    const __m128i b1 = _mm_srai_epi32(a1, 24);
    const __m128i c0 = _mm_cmpeq_epi32(b0, zero);
    const __m128i c1 = _mm_cmpeq_epi32(b1, zero);
    const __m128i d0 = _mm_and_si128(c0, m_color);
    const __m128i d1 = _mm_and_si128(c1, m_color);
    const __m128i e0 = _mm_andnot_si128(c0, a0);
    const __m128i e1 = _mm_andnot_si128(c1, a1);
    _mm_storeu_si128((__m128i*)(src + i + 0), _mm_or_si128(d0, e0));
    _mm_storeu_si128((__m128i*)(src + i + 4), _mm_or_si128(d1, e1));
  }
  for (; i < length; ++i) if ((src[i] >> 24) == 0) src[i] = color;
}

// -----------------------------------------------------------------------------
// Apply alpha value to rows

static void MultARGBRow_SSE2(uint32_t* const ptr, int width, int inverse) {
  int x = 0;
  if (!inverse) {
    const int kSpan = 2;
    const __m128i zero = _mm_setzero_si128();
    const __m128i k128 = _mm_set1_epi16(128);
    const __m128i kMult = _mm_set1_epi16(0x0101);
    const __m128i kMask = _mm_set_epi16(0, 0xff, 0, 0, 0, 0xff, 0, 0);
    for (x = 0; x + kSpan <= width; x += kSpan) {
      // To compute 'result = (int)(a * x / 255. + .5)', we use:
      //   tmp = a * v + 128, result = (tmp * 0x0101u) >> 16
      const __m128i A0 = _mm_loadl_epi64((const __m128i*)&ptr[x]);
      const __m128i A1 = _mm_unpacklo_epi8(A0, zero);
      const __m128i A2 = _mm_or_si128(A1, kMask);
      const __m128i A3 = _mm_shufflelo_epi16(A2, _MM_SHUFFLE(2, 3, 3, 3));
      const __m128i A4 = _mm_shufflehi_epi16(A3, _MM_SHUFFLE(2, 3, 3, 3));
      // here, A4 = [ff a0 a0 a0][ff a1 a1 a1]
      const __m128i A5 = _mm_mullo_epi16(A4, A1);
      const __m128i A6 = _mm_add_epi16(A5, k128);
      const __m128i A7 = _mm_mulhi_epu16(A6, kMult);
      const __m128i A10 = _mm_packus_epi16(A7, zero);
      _mm_storel_epi64((__m128i*)&ptr[x], A10);
    }
  }
  width -= x;
  if (width > 0) WebPMultARGBRow_C(ptr + x, width, inverse);
}

static void MultRow_SSE2(uint8_t* WEBP_RESTRICT const ptr,
                         const uint8_t* WEBP_RESTRICT const alpha,
                         int width, int inverse) {
  int x = 0;
  if (!inverse) {
    const __m128i zero = _mm_setzero_si128();
    const __m128i k128 = _mm_set1_epi16(128);
    const __m128i kMult = _mm_set1_epi16(0x0101);
    for (x = 0; x + 8 <= width; x += 8) {
      const __m128i v0 = _mm_loadl_epi64((__m128i*)&ptr[x]);
      const __m128i a0 = _mm_loadl_epi64((const __m128i*)&alpha[x]);
      const __m128i v1 = _mm_unpacklo_epi8(v0, zero);
      const __m128i a1 = _mm_unpacklo_epi8(a0, zero);
      const __m128i v2 = _mm_mullo_epi16(v1, a1);
      const __m128i v3 = _mm_add_epi16(v2, k128);
      const __m128i v4 = _mm_mulhi_epu16(v3, kMult);
      const __m128i v5 = _mm_packus_epi16(v4, zero);
      _mm_storel_epi64((__m128i*)&ptr[x], v5);
    }
  }
  width -= x;
  if (width > 0) WebPMultRow_C(ptr + x, alpha + x, width, inverse);
}

//------------------------------------------------------------------------------
// Entry point

extern void WebPInitAlphaProcessingSSE2(void);

WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessingSSE2(void) {
  WebPMultARGBRow = MultARGBRow_SSE2;
  WebPMultRow = MultRow_SSE2;
  WebPApplyAlphaMultiply = ApplyAlphaMultiply_SSE2;
  WebPDispatchAlpha = DispatchAlpha_SSE2;
  WebPDispatchAlphaToGreen = DispatchAlphaToGreen_SSE2;
  WebPExtractAlpha = ExtractAlpha_SSE2;

  WebPHasAlpha8b = HasAlpha8b_SSE2;
  WebPHasAlpha32b = HasAlpha32b_SSE2;
  WebPAlphaReplace = AlphaReplace_SSE2;
}

#else  // !WEBP_USE_SSE2

WEBP_DSP_INIT_STUB(WebPInitAlphaProcessingSSE2)

#endif  // WEBP_USE_SSE2