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 // NEON variant of methods for lossless decoder
11 //
12 // Author: Skal (pascal.massimino@gmail.com)
13
14 #include "./dsp.h"
15
16 #if defined(WEBP_USE_NEON)
17
18 #include <arm_neon.h>
19
20 #include "./lossless.h"
21 #include "./neon.h"
22
23 //------------------------------------------------------------------------------
24 // Colorspace conversion functions
25
26 #if !defined(WORK_AROUND_GCC)
27 // gcc 4.6.0 had some trouble (NDK-r9) with this code. We only use it for
28 // gcc-4.8.x at least.
ConvertBGRAToRGBA(const uint32_t * src,int num_pixels,uint8_t * dst)29 static void ConvertBGRAToRGBA(const uint32_t* src,
30 int num_pixels, uint8_t* dst) {
31 const uint32_t* const end = src + (num_pixels & ~15);
32 for (; src < end; src += 16) {
33 uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
34 // swap B and R. (VSWP d0,d2 has no intrinsics equivalent!)
35 const uint8x16_t tmp = pixel.val[0];
36 pixel.val[0] = pixel.val[2];
37 pixel.val[2] = tmp;
38 vst4q_u8(dst, pixel);
39 dst += 64;
40 }
41 VP8LConvertBGRAToRGBA_C(src, num_pixels & 15, dst); // left-overs
42 }
43
ConvertBGRAToBGR(const uint32_t * src,int num_pixels,uint8_t * dst)44 static void ConvertBGRAToBGR(const uint32_t* src,
45 int num_pixels, uint8_t* dst) {
46 const uint32_t* const end = src + (num_pixels & ~15);
47 for (; src < end; src += 16) {
48 const uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
49 const uint8x16x3_t tmp = { { pixel.val[0], pixel.val[1], pixel.val[2] } };
50 vst3q_u8(dst, tmp);
51 dst += 48;
52 }
53 VP8LConvertBGRAToBGR_C(src, num_pixels & 15, dst); // left-overs
54 }
55
ConvertBGRAToRGB(const uint32_t * src,int num_pixels,uint8_t * dst)56 static void ConvertBGRAToRGB(const uint32_t* src,
57 int num_pixels, uint8_t* dst) {
58 const uint32_t* const end = src + (num_pixels & ~15);
59 for (; src < end; src += 16) {
60 const uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
61 const uint8x16x3_t tmp = { { pixel.val[2], pixel.val[1], pixel.val[0] } };
62 vst3q_u8(dst, tmp);
63 dst += 48;
64 }
65 VP8LConvertBGRAToRGB_C(src, num_pixels & 15, dst); // left-overs
66 }
67
68 #else // WORK_AROUND_GCC
69
70 // gcc-4.6.0 fallback
71
72 static const uint8_t kRGBAShuffle[8] = { 2, 1, 0, 3, 6, 5, 4, 7 };
73
ConvertBGRAToRGBA(const uint32_t * src,int num_pixels,uint8_t * dst)74 static void ConvertBGRAToRGBA(const uint32_t* src,
75 int num_pixels, uint8_t* dst) {
76 const uint32_t* const end = src + (num_pixels & ~1);
77 const uint8x8_t shuffle = vld1_u8(kRGBAShuffle);
78 for (; src < end; src += 2) {
79 const uint8x8_t pixels = vld1_u8((uint8_t*)src);
80 vst1_u8(dst, vtbl1_u8(pixels, shuffle));
81 dst += 8;
82 }
83 VP8LConvertBGRAToRGBA_C(src, num_pixels & 1, dst); // left-overs
84 }
85
86 static const uint8_t kBGRShuffle[3][8] = {
87 { 0, 1, 2, 4, 5, 6, 8, 9 },
88 { 10, 12, 13, 14, 16, 17, 18, 20 },
89 { 21, 22, 24, 25, 26, 28, 29, 30 }
90 };
91
ConvertBGRAToBGR(const uint32_t * src,int num_pixels,uint8_t * dst)92 static void ConvertBGRAToBGR(const uint32_t* src,
93 int num_pixels, uint8_t* dst) {
94 const uint32_t* const end = src + (num_pixels & ~7);
95 const uint8x8_t shuffle0 = vld1_u8(kBGRShuffle[0]);
96 const uint8x8_t shuffle1 = vld1_u8(kBGRShuffle[1]);
97 const uint8x8_t shuffle2 = vld1_u8(kBGRShuffle[2]);
98 for (; src < end; src += 8) {
99 uint8x8x4_t pixels;
100 INIT_VECTOR4(pixels,
101 vld1_u8((const uint8_t*)(src + 0)),
102 vld1_u8((const uint8_t*)(src + 2)),
103 vld1_u8((const uint8_t*)(src + 4)),
104 vld1_u8((const uint8_t*)(src + 6)));
105 vst1_u8(dst + 0, vtbl4_u8(pixels, shuffle0));
106 vst1_u8(dst + 8, vtbl4_u8(pixels, shuffle1));
107 vst1_u8(dst + 16, vtbl4_u8(pixels, shuffle2));
108 dst += 8 * 3;
109 }
110 VP8LConvertBGRAToBGR_C(src, num_pixels & 7, dst); // left-overs
111 }
112
113 static const uint8_t kRGBShuffle[3][8] = {
114 { 2, 1, 0, 6, 5, 4, 10, 9 },
115 { 8, 14, 13, 12, 18, 17, 16, 22 },
116 { 21, 20, 26, 25, 24, 30, 29, 28 }
117 };
118
ConvertBGRAToRGB(const uint32_t * src,int num_pixels,uint8_t * dst)119 static void ConvertBGRAToRGB(const uint32_t* src,
120 int num_pixels, uint8_t* dst) {
121 const uint32_t* const end = src + (num_pixels & ~7);
122 const uint8x8_t shuffle0 = vld1_u8(kRGBShuffle[0]);
123 const uint8x8_t shuffle1 = vld1_u8(kRGBShuffle[1]);
124 const uint8x8_t shuffle2 = vld1_u8(kRGBShuffle[2]);
125 for (; src < end; src += 8) {
126 uint8x8x4_t pixels;
127 INIT_VECTOR4(pixels,
128 vld1_u8((const uint8_t*)(src + 0)),
129 vld1_u8((const uint8_t*)(src + 2)),
130 vld1_u8((const uint8_t*)(src + 4)),
131 vld1_u8((const uint8_t*)(src + 6)));
132 vst1_u8(dst + 0, vtbl4_u8(pixels, shuffle0));
133 vst1_u8(dst + 8, vtbl4_u8(pixels, shuffle1));
134 vst1_u8(dst + 16, vtbl4_u8(pixels, shuffle2));
135 dst += 8 * 3;
136 }
137 VP8LConvertBGRAToRGB_C(src, num_pixels & 7, dst); // left-overs
138 }
139
140 #endif // !WORK_AROUND_GCC
141
142
143 //------------------------------------------------------------------------------
144 // Predictor Transform
145
146 #define LOAD_U32_AS_U8(IN) vreinterpret_u8_u32(vdup_n_u32((IN)))
147 #define LOAD_U32P_AS_U8(IN) vreinterpret_u8_u32(vld1_u32((IN)))
148 #define LOADQ_U32_AS_U8(IN) vreinterpretq_u8_u32(vdupq_n_u32((IN)))
149 #define LOADQ_U32P_AS_U8(IN) vreinterpretq_u8_u32(vld1q_u32((IN)))
150 #define GET_U8_AS_U32(IN) vget_lane_u32(vreinterpret_u32_u8((IN)), 0);
151 #define GETQ_U8_AS_U32(IN) vgetq_lane_u32(vreinterpretq_u32_u8((IN)), 0);
152 #define STOREQ_U8_AS_U32P(OUT, IN) vst1q_u32((OUT), vreinterpretq_u32_u8((IN)));
153 #define ROTATE32_LEFT(L) vextq_u8((L), (L), 12) // D|C|B|A -> C|B|A|D
154
Average2_u8_NEON(uint32_t a0,uint32_t a1)155 static WEBP_INLINE uint8x8_t Average2_u8_NEON(uint32_t a0, uint32_t a1) {
156 const uint8x8_t A0 = LOAD_U32_AS_U8(a0);
157 const uint8x8_t A1 = LOAD_U32_AS_U8(a1);
158 return vhadd_u8(A0, A1);
159 }
160
ClampedAddSubtractHalf_NEON(uint32_t c0,uint32_t c1,uint32_t c2)161 static WEBP_INLINE uint32_t ClampedAddSubtractHalf_NEON(uint32_t c0,
162 uint32_t c1,
163 uint32_t c2) {
164 const uint8x8_t avg = Average2_u8_NEON(c0, c1);
165 // Remove one to c2 when bigger than avg.
166 const uint8x8_t C2 = LOAD_U32_AS_U8(c2);
167 const uint8x8_t cmp = vcgt_u8(C2, avg);
168 const uint8x8_t C2_1 = vadd_u8(C2, cmp);
169 // Compute half of the difference between avg and c2.
170 const int8x8_t diff_avg = vreinterpret_s8_u8(vhsub_u8(avg, C2_1));
171 // Compute the sum with avg and saturate.
172 const int16x8_t avg_16 = vreinterpretq_s16_u16(vmovl_u8(avg));
173 const uint8x8_t res = vqmovun_s16(vaddw_s8(avg_16, diff_avg));
174 const uint32_t output = GET_U8_AS_U32(res);
175 return output;
176 }
177
Average2_NEON(uint32_t a0,uint32_t a1)178 static WEBP_INLINE uint32_t Average2_NEON(uint32_t a0, uint32_t a1) {
179 const uint8x8_t avg_u8x8 = Average2_u8_NEON(a0, a1);
180 const uint32_t avg = GET_U8_AS_U32(avg_u8x8);
181 return avg;
182 }
183
Average3_NEON(uint32_t a0,uint32_t a1,uint32_t a2)184 static WEBP_INLINE uint32_t Average3_NEON(uint32_t a0, uint32_t a1,
185 uint32_t a2) {
186 const uint8x8_t avg0 = Average2_u8_NEON(a0, a2);
187 const uint8x8_t A1 = LOAD_U32_AS_U8(a1);
188 const uint32_t avg = GET_U8_AS_U32(vhadd_u8(avg0, A1));
189 return avg;
190 }
191
Predictor5_NEON(uint32_t left,const uint32_t * const top)192 static uint32_t Predictor5_NEON(uint32_t left, const uint32_t* const top) {
193 return Average3_NEON(left, top[0], top[1]);
194 }
Predictor6_NEON(uint32_t left,const uint32_t * const top)195 static uint32_t Predictor6_NEON(uint32_t left, const uint32_t* const top) {
196 return Average2_NEON(left, top[-1]);
197 }
Predictor7_NEON(uint32_t left,const uint32_t * const top)198 static uint32_t Predictor7_NEON(uint32_t left, const uint32_t* const top) {
199 return Average2_NEON(left, top[0]);
200 }
Predictor13_NEON(uint32_t left,const uint32_t * const top)201 static uint32_t Predictor13_NEON(uint32_t left, const uint32_t* const top) {
202 return ClampedAddSubtractHalf_NEON(left, top[0], top[-1]);
203 }
204
205 // Batch versions of those functions.
206
207 // Predictor0: ARGB_BLACK.
PredictorAdd0_NEON(const uint32_t * in,const uint32_t * upper,int num_pixels,uint32_t * out)208 static void PredictorAdd0_NEON(const uint32_t* in, const uint32_t* upper,
209 int num_pixels, uint32_t* out) {
210 int i;
211 const uint8x16_t black = vreinterpretq_u8_u32(vdupq_n_u32(ARGB_BLACK));
212 for (i = 0; i + 4 <= num_pixels; i += 4) {
213 const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]);
214 const uint8x16_t res = vaddq_u8(src, black);
215 STOREQ_U8_AS_U32P(&out[i], res);
216 }
217 VP8LPredictorsAdd_C[0](in + i, upper + i, num_pixels - i, out + i);
218 }
219
220 // Predictor1: left.
PredictorAdd1_NEON(const uint32_t * in,const uint32_t * upper,int num_pixels,uint32_t * out)221 static void PredictorAdd1_NEON(const uint32_t* in, const uint32_t* upper,
222 int num_pixels, uint32_t* out) {
223 int i;
224 const uint8x16_t zero = LOADQ_U32_AS_U8(0);
225 for (i = 0; i + 4 <= num_pixels; i += 4) {
226 // a | b | c | d
227 const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]);
228 // 0 | a | b | c
229 const uint8x16_t shift0 = vextq_u8(zero, src, 12);
230 // a | a + b | b + c | c + d
231 const uint8x16_t sum0 = vaddq_u8(src, shift0);
232 // 0 | 0 | a | a + b
233 const uint8x16_t shift1 = vextq_u8(zero, sum0, 8);
234 // a | a + b | a + b + c | a + b + c + d
235 const uint8x16_t sum1 = vaddq_u8(sum0, shift1);
236 const uint8x16_t prev = LOADQ_U32_AS_U8(out[i - 1]);
237 const uint8x16_t res = vaddq_u8(sum1, prev);
238 STOREQ_U8_AS_U32P(&out[i], res);
239 }
240 VP8LPredictorsAdd_C[1](in + i, upper + i, num_pixels - i, out + i);
241 }
242
243 // Macro that adds 32-bit integers from IN using mod 256 arithmetic
244 // per 8 bit channel.
245 #define GENERATE_PREDICTOR_1(X, IN) \
246 static void PredictorAdd##X##_NEON(const uint32_t* in, \
247 const uint32_t* upper, int num_pixels, \
248 uint32_t* out) { \
249 int i; \
250 for (i = 0; i + 4 <= num_pixels; i += 4) { \
251 const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]); \
252 const uint8x16_t other = LOADQ_U32P_AS_U8(&(IN)); \
253 const uint8x16_t res = vaddq_u8(src, other); \
254 STOREQ_U8_AS_U32P(&out[i], res); \
255 } \
256 VP8LPredictorsAdd_C[(X)](in + i, upper + i, num_pixels - i, out + i); \
257 }
258 // Predictor2: Top.
259 GENERATE_PREDICTOR_1(2, upper[i])
260 // Predictor3: Top-right.
261 GENERATE_PREDICTOR_1(3, upper[i + 1])
262 // Predictor4: Top-left.
263 GENERATE_PREDICTOR_1(4, upper[i - 1])
264 #undef GENERATE_PREDICTOR_1
265
266 // Predictor5: average(average(left, TR), T)
267 #define DO_PRED5(LANE) do { \
268 const uint8x16_t avgLTR = vhaddq_u8(L, TR); \
269 const uint8x16_t avg = vhaddq_u8(avgLTR, T); \
270 const uint8x16_t res = vaddq_u8(avg, src); \
271 vst1q_lane_u32(&out[i + (LANE)], vreinterpretq_u32_u8(res), (LANE)); \
272 L = ROTATE32_LEFT(res); \
273 } while (0)
274
PredictorAdd5_NEON(const uint32_t * in,const uint32_t * upper,int num_pixels,uint32_t * out)275 static void PredictorAdd5_NEON(const uint32_t* in, const uint32_t* upper,
276 int num_pixels, uint32_t* out) {
277 int i;
278 uint8x16_t L = LOADQ_U32_AS_U8(out[-1]);
279 for (i = 0; i + 4 <= num_pixels; i += 4) {
280 const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]);
281 const uint8x16_t T = LOADQ_U32P_AS_U8(&upper[i + 0]);
282 const uint8x16_t TR = LOADQ_U32P_AS_U8(&upper[i + 1]);
283 DO_PRED5(0);
284 DO_PRED5(1);
285 DO_PRED5(2);
286 DO_PRED5(3);
287 }
288 VP8LPredictorsAdd_C[5](in + i, upper + i, num_pixels - i, out + i);
289 }
290 #undef DO_PRED5
291
292 #define DO_PRED67(LANE) do { \
293 const uint8x16_t avg = vhaddq_u8(L, top); \
294 const uint8x16_t res = vaddq_u8(avg, src); \
295 vst1q_lane_u32(&out[i + (LANE)], vreinterpretq_u32_u8(res), (LANE)); \
296 L = ROTATE32_LEFT(res); \
297 } while (0)
298
299 // Predictor6: average(left, TL)
PredictorAdd6_NEON(const uint32_t * in,const uint32_t * upper,int num_pixels,uint32_t * out)300 static void PredictorAdd6_NEON(const uint32_t* in, const uint32_t* upper,
301 int num_pixels, uint32_t* out) {
302 int i;
303 uint8x16_t L = LOADQ_U32_AS_U8(out[-1]);
304 for (i = 0; i + 4 <= num_pixels; i += 4) {
305 const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]);
306 const uint8x16_t top = LOADQ_U32P_AS_U8(&upper[i - 1]);
307 DO_PRED67(0);
308 DO_PRED67(1);
309 DO_PRED67(2);
310 DO_PRED67(3);
311 }
312 VP8LPredictorsAdd_C[6](in + i, upper + i, num_pixels - i, out + i);
313 }
314
315 // Predictor7: average(left, T)
PredictorAdd7_NEON(const uint32_t * in,const uint32_t * upper,int num_pixels,uint32_t * out)316 static void PredictorAdd7_NEON(const uint32_t* in, const uint32_t* upper,
317 int num_pixels, uint32_t* out) {
318 int i;
319 uint8x16_t L = LOADQ_U32_AS_U8(out[-1]);
320 for (i = 0; i + 4 <= num_pixels; i += 4) {
321 const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]);
322 const uint8x16_t top = LOADQ_U32P_AS_U8(&upper[i]);
323 DO_PRED67(0);
324 DO_PRED67(1);
325 DO_PRED67(2);
326 DO_PRED67(3);
327 }
328 VP8LPredictorsAdd_C[7](in + i, upper + i, num_pixels - i, out + i);
329 }
330 #undef DO_PRED67
331
332 #define GENERATE_PREDICTOR_2(X, IN) \
333 static void PredictorAdd##X##_NEON(const uint32_t* in, \
334 const uint32_t* upper, int num_pixels, \
335 uint32_t* out) { \
336 int i; \
337 for (i = 0; i + 4 <= num_pixels; i += 4) { \
338 const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]); \
339 const uint8x16_t Tother = LOADQ_U32P_AS_U8(&(IN)); \
340 const uint8x16_t T = LOADQ_U32P_AS_U8(&upper[i]); \
341 const uint8x16_t avg = vhaddq_u8(T, Tother); \
342 const uint8x16_t res = vaddq_u8(avg, src); \
343 STOREQ_U8_AS_U32P(&out[i], res); \
344 } \
345 VP8LPredictorsAdd_C[(X)](in + i, upper + i, num_pixels - i, out + i); \
346 }
347 // Predictor8: average TL T.
348 GENERATE_PREDICTOR_2(8, upper[i - 1])
349 // Predictor9: average T TR.
350 GENERATE_PREDICTOR_2(9, upper[i + 1])
351 #undef GENERATE_PREDICTOR_2
352
353 // Predictor10: average of (average of (L,TL), average of (T, TR)).
354 #define DO_PRED10(LANE) do { \
355 const uint8x16_t avgLTL = vhaddq_u8(L, TL); \
356 const uint8x16_t avg = vhaddq_u8(avgTTR, avgLTL); \
357 const uint8x16_t res = vaddq_u8(avg, src); \
358 vst1q_lane_u32(&out[i + (LANE)], vreinterpretq_u32_u8(res), (LANE)); \
359 L = ROTATE32_LEFT(res); \
360 } while (0)
361
PredictorAdd10_NEON(const uint32_t * in,const uint32_t * upper,int num_pixels,uint32_t * out)362 static void PredictorAdd10_NEON(const uint32_t* in, const uint32_t* upper,
363 int num_pixels, uint32_t* out) {
364 int i;
365 uint8x16_t L = LOADQ_U32_AS_U8(out[-1]);
366 for (i = 0; i + 4 <= num_pixels; i += 4) {
367 const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]);
368 const uint8x16_t TL = LOADQ_U32P_AS_U8(&upper[i - 1]);
369 const uint8x16_t T = LOADQ_U32P_AS_U8(&upper[i]);
370 const uint8x16_t TR = LOADQ_U32P_AS_U8(&upper[i + 1]);
371 const uint8x16_t avgTTR = vhaddq_u8(T, TR);
372 DO_PRED10(0);
373 DO_PRED10(1);
374 DO_PRED10(2);
375 DO_PRED10(3);
376 }
377 VP8LPredictorsAdd_C[10](in + i, upper + i, num_pixels - i, out + i);
378 }
379 #undef DO_PRED10
380
381 // Predictor11: select.
382 #define DO_PRED11(LANE) do { \
383 const uint8x16_t sumLin = vaddq_u8(L, src); /* in + L */ \
384 const uint8x16_t pLTL = vabdq_u8(L, TL); /* |L - TL| */ \
385 const uint16x8_t sum_LTL = vpaddlq_u8(pLTL); \
386 const uint32x4_t pa = vpaddlq_u16(sum_LTL); \
387 const uint32x4_t mask = vcleq_u32(pa, pb); \
388 const uint8x16_t res = vbslq_u8(vreinterpretq_u8_u32(mask), sumTin, sumLin); \
389 vst1q_lane_u32(&out[i + (LANE)], vreinterpretq_u32_u8(res), (LANE)); \
390 L = ROTATE32_LEFT(res); \
391 } while (0)
392
PredictorAdd11_NEON(const uint32_t * in,const uint32_t * upper,int num_pixels,uint32_t * out)393 static void PredictorAdd11_NEON(const uint32_t* in, const uint32_t* upper,
394 int num_pixels, uint32_t* out) {
395 int i;
396 uint8x16_t L = LOADQ_U32_AS_U8(out[-1]);
397 for (i = 0; i + 4 <= num_pixels; i += 4) {
398 const uint8x16_t T = LOADQ_U32P_AS_U8(&upper[i]);
399 const uint8x16_t TL = LOADQ_U32P_AS_U8(&upper[i - 1]);
400 const uint8x16_t pTTL = vabdq_u8(T, TL); // |T - TL|
401 const uint16x8_t sum_TTL = vpaddlq_u8(pTTL);
402 const uint32x4_t pb = vpaddlq_u16(sum_TTL);
403 const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]);
404 const uint8x16_t sumTin = vaddq_u8(T, src); // in + T
405 DO_PRED11(0);
406 DO_PRED11(1);
407 DO_PRED11(2);
408 DO_PRED11(3);
409 }
410 VP8LPredictorsAdd_C[11](in + i, upper + i, num_pixels - i, out + i);
411 }
412 #undef DO_PRED11
413
414 // Predictor12: ClampedAddSubtractFull.
415 #define DO_PRED12(DIFF, LANE) do { \
416 const uint8x8_t pred = \
417 vqmovun_s16(vaddq_s16(vreinterpretq_s16_u16(L), (DIFF))); \
418 const uint8x8_t res = \
419 vadd_u8(pred, (LANE <= 1) ? vget_low_u8(src) : vget_high_u8(src)); \
420 const uint16x8_t res16 = vmovl_u8(res); \
421 vst1_lane_u32(&out[i + (LANE)], vreinterpret_u32_u8(res), (LANE) & 1); \
422 /* rotate in the left predictor for next iteration */ \
423 L = vextq_u16(res16, res16, 4); \
424 } while (0)
425
PredictorAdd12_NEON(const uint32_t * in,const uint32_t * upper,int num_pixels,uint32_t * out)426 static void PredictorAdd12_NEON(const uint32_t* in, const uint32_t* upper,
427 int num_pixels, uint32_t* out) {
428 int i;
429 uint16x8_t L = vmovl_u8(LOAD_U32_AS_U8(out[-1]));
430 for (i = 0; i + 4 <= num_pixels; i += 4) {
431 // load four pixels of source
432 const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]);
433 // precompute the difference T - TL once for all, stored as s16
434 const uint8x16_t TL = LOADQ_U32P_AS_U8(&upper[i - 1]);
435 const uint8x16_t T = LOADQ_U32P_AS_U8(&upper[i]);
436 const int16x8_t diff_lo =
437 vreinterpretq_s16_u16(vsubl_u8(vget_low_u8(T), vget_low_u8(TL)));
438 const int16x8_t diff_hi =
439 vreinterpretq_s16_u16(vsubl_u8(vget_high_u8(T), vget_high_u8(TL)));
440 // loop over the four reconstructed pixels
441 DO_PRED12(diff_lo, 0);
442 DO_PRED12(diff_lo, 1);
443 DO_PRED12(diff_hi, 2);
444 DO_PRED12(diff_hi, 3);
445 }
446 VP8LPredictorsAdd_C[12](in + i, upper + i, num_pixels - i, out + i);
447 }
448 #undef DO_PRED12
449
450 // Predictor13: ClampedAddSubtractHalf
451 #define DO_PRED13(LANE, LOW_OR_HI) do { \
452 const uint8x16_t avg = vhaddq_u8(L, T); \
453 const uint8x16_t cmp = vcgtq_u8(TL, avg); \
454 const uint8x16_t TL_1 = vaddq_u8(TL, cmp); \
455 /* Compute half of the difference between avg and TL'. */ \
456 const int8x8_t diff_avg = \
457 vreinterpret_s8_u8(LOW_OR_HI(vhsubq_u8(avg, TL_1))); \
458 /* Compute the sum with avg and saturate. */ \
459 const int16x8_t avg_16 = vreinterpretq_s16_u16(vmovl_u8(LOW_OR_HI(avg))); \
460 const uint8x8_t delta = vqmovun_s16(vaddw_s8(avg_16, diff_avg)); \
461 const uint8x8_t res = vadd_u8(LOW_OR_HI(src), delta); \
462 const uint8x16_t res2 = vcombine_u8(res, res); \
463 vst1_lane_u32(&out[i + (LANE)], vreinterpret_u32_u8(res), (LANE) & 1); \
464 L = ROTATE32_LEFT(res2); \
465 } while (0)
466
PredictorAdd13_NEON(const uint32_t * in,const uint32_t * upper,int num_pixels,uint32_t * out)467 static void PredictorAdd13_NEON(const uint32_t* in, const uint32_t* upper,
468 int num_pixels, uint32_t* out) {
469 int i;
470 uint8x16_t L = LOADQ_U32_AS_U8(out[-1]);
471 for (i = 0; i + 4 <= num_pixels; i += 4) {
472 const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]);
473 const uint8x16_t T = LOADQ_U32P_AS_U8(&upper[i]);
474 const uint8x16_t TL = LOADQ_U32P_AS_U8(&upper[i - 1]);
475 DO_PRED13(0, vget_low_u8);
476 DO_PRED13(1, vget_low_u8);
477 DO_PRED13(2, vget_high_u8);
478 DO_PRED13(3, vget_high_u8);
479 }
480 VP8LPredictorsAdd_C[13](in + i, upper + i, num_pixels - i, out + i);
481 }
482 #undef DO_PRED13
483
484 #undef LOAD_U32_AS_U8
485 #undef LOAD_U32P_AS_U8
486 #undef LOADQ_U32_AS_U8
487 #undef LOADQ_U32P_AS_U8
488 #undef GET_U8_AS_U32
489 #undef GETQ_U8_AS_U32
490 #undef STOREQ_U8_AS_U32P
491 #undef ROTATE32_LEFT
492
493 //------------------------------------------------------------------------------
494 // Subtract-Green Transform
495
496 // vtbl?_u8 are marked unavailable for iOS arm64 with Xcode < 6.3, use
497 // non-standard versions there.
498 #if defined(__APPLE__) && defined(__aarch64__) && \
499 defined(__apple_build_version__) && (__apple_build_version__< 6020037)
500 #define USE_VTBLQ
501 #endif
502
503 #ifdef USE_VTBLQ
504 // 255 = byte will be zeroed
505 static const uint8_t kGreenShuffle[16] = {
506 1, 255, 1, 255, 5, 255, 5, 255, 9, 255, 9, 255, 13, 255, 13, 255
507 };
508
DoGreenShuffle(const uint8x16_t argb,const uint8x16_t shuffle)509 static WEBP_INLINE uint8x16_t DoGreenShuffle(const uint8x16_t argb,
510 const uint8x16_t shuffle) {
511 return vcombine_u8(vtbl1q_u8(argb, vget_low_u8(shuffle)),
512 vtbl1q_u8(argb, vget_high_u8(shuffle)));
513 }
514 #else // !USE_VTBLQ
515 // 255 = byte will be zeroed
516 static const uint8_t kGreenShuffle[8] = { 1, 255, 1, 255, 5, 255, 5, 255 };
517
DoGreenShuffle(const uint8x16_t argb,const uint8x8_t shuffle)518 static WEBP_INLINE uint8x16_t DoGreenShuffle(const uint8x16_t argb,
519 const uint8x8_t shuffle) {
520 return vcombine_u8(vtbl1_u8(vget_low_u8(argb), shuffle),
521 vtbl1_u8(vget_high_u8(argb), shuffle));
522 }
523 #endif // USE_VTBLQ
524
AddGreenToBlueAndRed(const uint32_t * src,int num_pixels,uint32_t * dst)525 static void AddGreenToBlueAndRed(const uint32_t* src, int num_pixels,
526 uint32_t* dst) {
527 const uint32_t* const end = src + (num_pixels & ~3);
528 #ifdef USE_VTBLQ
529 const uint8x16_t shuffle = vld1q_u8(kGreenShuffle);
530 #else
531 const uint8x8_t shuffle = vld1_u8(kGreenShuffle);
532 #endif
533 for (; src < end; src += 4, dst += 4) {
534 const uint8x16_t argb = vld1q_u8((const uint8_t*)src);
535 const uint8x16_t greens = DoGreenShuffle(argb, shuffle);
536 vst1q_u8((uint8_t*)dst, vaddq_u8(argb, greens));
537 }
538 // fallthrough and finish off with plain-C
539 VP8LAddGreenToBlueAndRed_C(src, num_pixels & 3, dst);
540 }
541
542 //------------------------------------------------------------------------------
543 // Color Transform
544
TransformColorInverse(const VP8LMultipliers * const m,const uint32_t * const src,int num_pixels,uint32_t * dst)545 static void TransformColorInverse(const VP8LMultipliers* const m,
546 const uint32_t* const src, int num_pixels,
547 uint32_t* dst) {
548 // sign-extended multiplying constants, pre-shifted by 6.
549 #define CST(X) (((int16_t)(m->X << 8)) >> 6)
550 const int16_t rb[8] = {
551 CST(green_to_blue_), CST(green_to_red_),
552 CST(green_to_blue_), CST(green_to_red_),
553 CST(green_to_blue_), CST(green_to_red_),
554 CST(green_to_blue_), CST(green_to_red_)
555 };
556 const int16x8_t mults_rb = vld1q_s16(rb);
557 const int16_t b2[8] = {
558 0, CST(red_to_blue_), 0, CST(red_to_blue_),
559 0, CST(red_to_blue_), 0, CST(red_to_blue_),
560 };
561 const int16x8_t mults_b2 = vld1q_s16(b2);
562 #undef CST
563 #ifdef USE_VTBLQ
564 static const uint8_t kg0g0[16] = {
565 255, 1, 255, 1, 255, 5, 255, 5, 255, 9, 255, 9, 255, 13, 255, 13
566 };
567 const uint8x16_t shuffle = vld1q_u8(kg0g0);
568 #else
569 static const uint8_t k0g0g[8] = { 255, 1, 255, 1, 255, 5, 255, 5 };
570 const uint8x8_t shuffle = vld1_u8(k0g0g);
571 #endif
572 const uint32x4_t mask_ag = vdupq_n_u32(0xff00ff00u);
573 int i;
574 for (i = 0; i + 4 <= num_pixels; i += 4) {
575 const uint8x16_t in = vld1q_u8((const uint8_t*)(src + i));
576 const uint32x4_t a0g0 = vandq_u32(vreinterpretq_u32_u8(in), mask_ag);
577 // 0 g 0 g
578 const uint8x16_t greens = DoGreenShuffle(in, shuffle);
579 // x dr x db1
580 const int16x8_t A = vqdmulhq_s16(vreinterpretq_s16_u8(greens), mults_rb);
581 // x r' x b'
582 const int8x16_t B = vaddq_s8(vreinterpretq_s8_u8(in),
583 vreinterpretq_s8_s16(A));
584 // r' 0 b' 0
585 const int16x8_t C = vshlq_n_s16(vreinterpretq_s16_s8(B), 8);
586 // x db2 0 0
587 const int16x8_t D = vqdmulhq_s16(C, mults_b2);
588 // 0 x db2 0
589 const uint32x4_t E = vshrq_n_u32(vreinterpretq_u32_s16(D), 8);
590 // r' x b'' 0
591 const int8x16_t F = vaddq_s8(vreinterpretq_s8_u32(E),
592 vreinterpretq_s8_s16(C));
593 // 0 r' 0 b''
594 const uint16x8_t G = vshrq_n_u16(vreinterpretq_u16_s8(F), 8);
595 const uint32x4_t out = vorrq_u32(vreinterpretq_u32_u16(G), a0g0);
596 vst1q_u32(dst + i, out);
597 }
598 // Fall-back to C-version for left-overs.
599 VP8LTransformColorInverse_C(m, src + i, num_pixels - i, dst + i);
600 }
601
602 #undef USE_VTBLQ
603
604 //------------------------------------------------------------------------------
605 // Entry point
606
607 extern void VP8LDspInitNEON(void);
608
VP8LDspInitNEON(void)609 WEBP_TSAN_IGNORE_FUNCTION void VP8LDspInitNEON(void) {
610 VP8LPredictors[5] = Predictor5_NEON;
611 VP8LPredictors[6] = Predictor6_NEON;
612 VP8LPredictors[7] = Predictor7_NEON;
613 VP8LPredictors[13] = Predictor13_NEON;
614
615 VP8LPredictorsAdd[0] = PredictorAdd0_NEON;
616 VP8LPredictorsAdd[1] = PredictorAdd1_NEON;
617 VP8LPredictorsAdd[2] = PredictorAdd2_NEON;
618 VP8LPredictorsAdd[3] = PredictorAdd3_NEON;
619 VP8LPredictorsAdd[4] = PredictorAdd4_NEON;
620 VP8LPredictorsAdd[5] = PredictorAdd5_NEON;
621 VP8LPredictorsAdd[6] = PredictorAdd6_NEON;
622 VP8LPredictorsAdd[7] = PredictorAdd7_NEON;
623 VP8LPredictorsAdd[8] = PredictorAdd8_NEON;
624 VP8LPredictorsAdd[9] = PredictorAdd9_NEON;
625 VP8LPredictorsAdd[10] = PredictorAdd10_NEON;
626 VP8LPredictorsAdd[11] = PredictorAdd11_NEON;
627 VP8LPredictorsAdd[12] = PredictorAdd12_NEON;
628 VP8LPredictorsAdd[13] = PredictorAdd13_NEON;
629
630 VP8LConvertBGRAToRGBA = ConvertBGRAToRGBA;
631 VP8LConvertBGRAToBGR = ConvertBGRAToBGR;
632 VP8LConvertBGRAToRGB = ConvertBGRAToRGB;
633
634 VP8LAddGreenToBlueAndRed = AddGreenToBlueAndRed;
635 VP8LTransformColorInverse = TransformColorInverse;
636 }
637
638 #else // !WEBP_USE_NEON
639
640 WEBP_DSP_INIT_STUB(VP8LDspInitNEON)
641
642 #endif // WEBP_USE_NEON
643