summaryrefslogtreecommitdiffstats
path: root/media/libwebp/src/dsp/dec_neon.c
blob: 22784cf15ae91b2918acec1adcf14fcb573964bc (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
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
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
// Copyright 2012 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.
// -----------------------------------------------------------------------------
//
// ARM NEON version of dsp functions and loop filtering.
//
// Authors: Somnath Banerjee (somnath@google.com)
//          Johann Koenig (johannkoenig@google.com)

#include "src/dsp/dsp.h"

#if defined(WEBP_USE_NEON)

#include "src/dsp/neon.h"
#include "src/dec/vp8i_dec.h"

//------------------------------------------------------------------------------
// NxM Loading functions

#if !defined(WORK_AROUND_GCC)

// This intrinsics version makes gcc-4.6.3 crash during Load4x??() compilation
// (register alloc, probably). The variants somewhat mitigate the problem, but
// not quite. HFilter16i() remains problematic.
static WEBP_INLINE uint8x8x4_t Load4x8_NEON(const uint8_t* const src,
                                            int stride) {
  const uint8x8_t zero = vdup_n_u8(0);
  uint8x8x4_t out;
  INIT_VECTOR4(out, zero, zero, zero, zero);
  out = vld4_lane_u8(src + 0 * stride, out, 0);
  out = vld4_lane_u8(src + 1 * stride, out, 1);
  out = vld4_lane_u8(src + 2 * stride, out, 2);
  out = vld4_lane_u8(src + 3 * stride, out, 3);
  out = vld4_lane_u8(src + 4 * stride, out, 4);
  out = vld4_lane_u8(src + 5 * stride, out, 5);
  out = vld4_lane_u8(src + 6 * stride, out, 6);
  out = vld4_lane_u8(src + 7 * stride, out, 7);
  return out;
}

static WEBP_INLINE void Load4x16_NEON(const uint8_t* const src, int stride,
                                      uint8x16_t* const p1,
                                      uint8x16_t* const p0,
                                      uint8x16_t* const q0,
                                      uint8x16_t* const q1) {
  // row0 = p1[0..7]|p0[0..7]|q0[0..7]|q1[0..7]
  // row8 = p1[8..15]|p0[8..15]|q0[8..15]|q1[8..15]
  const uint8x8x4_t row0 = Load4x8_NEON(src - 2 + 0 * stride, stride);
  const uint8x8x4_t row8 = Load4x8_NEON(src - 2 + 8 * stride, stride);
  *p1 = vcombine_u8(row0.val[0], row8.val[0]);
  *p0 = vcombine_u8(row0.val[1], row8.val[1]);
  *q0 = vcombine_u8(row0.val[2], row8.val[2]);
  *q1 = vcombine_u8(row0.val[3], row8.val[3]);
}

#else  // WORK_AROUND_GCC

#define LOADQ_LANE_32b(VALUE, LANE) do {                             \
  (VALUE) = vld1q_lane_u32((const uint32_t*)src, (VALUE), (LANE));   \
  src += stride;                                                     \
} while (0)

static WEBP_INLINE void Load4x16_NEON(const uint8_t* src, int stride,
                                      uint8x16_t* const p1,
                                      uint8x16_t* const p0,
                                      uint8x16_t* const q0,
                                      uint8x16_t* const q1) {
  const uint32x4_t zero = vdupq_n_u32(0);
  uint32x4x4_t in;
  INIT_VECTOR4(in, zero, zero, zero, zero);
  src -= 2;
  LOADQ_LANE_32b(in.val[0], 0);
  LOADQ_LANE_32b(in.val[1], 0);
  LOADQ_LANE_32b(in.val[2], 0);
  LOADQ_LANE_32b(in.val[3], 0);
  LOADQ_LANE_32b(in.val[0], 1);
  LOADQ_LANE_32b(in.val[1], 1);
  LOADQ_LANE_32b(in.val[2], 1);
  LOADQ_LANE_32b(in.val[3], 1);
  LOADQ_LANE_32b(in.val[0], 2);
  LOADQ_LANE_32b(in.val[1], 2);
  LOADQ_LANE_32b(in.val[2], 2);
  LOADQ_LANE_32b(in.val[3], 2);
  LOADQ_LANE_32b(in.val[0], 3);
  LOADQ_LANE_32b(in.val[1], 3);
  LOADQ_LANE_32b(in.val[2], 3);
  LOADQ_LANE_32b(in.val[3], 3);
  // Transpose four 4x4 parts:
  {
    const uint8x16x2_t row01 = vtrnq_u8(vreinterpretq_u8_u32(in.val[0]),
                                        vreinterpretq_u8_u32(in.val[1]));
    const uint8x16x2_t row23 = vtrnq_u8(vreinterpretq_u8_u32(in.val[2]),
                                        vreinterpretq_u8_u32(in.val[3]));
    const uint16x8x2_t row02 = vtrnq_u16(vreinterpretq_u16_u8(row01.val[0]),
                                         vreinterpretq_u16_u8(row23.val[0]));
    const uint16x8x2_t row13 = vtrnq_u16(vreinterpretq_u16_u8(row01.val[1]),
                                         vreinterpretq_u16_u8(row23.val[1]));
    *p1 = vreinterpretq_u8_u16(row02.val[0]);
    *p0 = vreinterpretq_u8_u16(row13.val[0]);
    *q0 = vreinterpretq_u8_u16(row02.val[1]);
    *q1 = vreinterpretq_u8_u16(row13.val[1]);
  }
}
#undef LOADQ_LANE_32b

#endif  // !WORK_AROUND_GCC

static WEBP_INLINE void Load8x16_NEON(
    const uint8_t* const src, int stride,
    uint8x16_t* const p3, uint8x16_t* const p2, uint8x16_t* const p1,
    uint8x16_t* const p0, uint8x16_t* const q0, uint8x16_t* const q1,
    uint8x16_t* const q2, uint8x16_t* const q3) {
  Load4x16_NEON(src - 2, stride, p3, p2, p1, p0);
  Load4x16_NEON(src + 2, stride, q0, q1, q2, q3);
}

static WEBP_INLINE void Load16x4_NEON(const uint8_t* const src, int stride,
                                      uint8x16_t* const p1,
                                      uint8x16_t* const p0,
                                      uint8x16_t* const q0,
                                      uint8x16_t* const q1) {
  *p1 = vld1q_u8(src - 2 * stride);
  *p0 = vld1q_u8(src - 1 * stride);
  *q0 = vld1q_u8(src + 0 * stride);
  *q1 = vld1q_u8(src + 1 * stride);
}

static WEBP_INLINE void Load16x8_NEON(
    const uint8_t* const src, int stride,
    uint8x16_t* const p3, uint8x16_t* const p2, uint8x16_t* const p1,
    uint8x16_t* const p0, uint8x16_t* const q0, uint8x16_t* const q1,
    uint8x16_t* const q2, uint8x16_t* const q3) {
  Load16x4_NEON(src - 2  * stride, stride, p3, p2, p1, p0);
  Load16x4_NEON(src + 2  * stride, stride, q0, q1, q2, q3);
}

static WEBP_INLINE void Load8x8x2_NEON(
    const uint8_t* const u, const uint8_t* const v, int stride,
    uint8x16_t* const p3, uint8x16_t* const p2, uint8x16_t* const p1,
    uint8x16_t* const p0, uint8x16_t* const q0, uint8x16_t* const q1,
    uint8x16_t* const q2, uint8x16_t* const q3) {
  // We pack the 8x8 u-samples in the lower half of the uint8x16_t destination
  // and the v-samples on the higher half.
  *p3 = vcombine_u8(vld1_u8(u - 4 * stride), vld1_u8(v - 4 * stride));
  *p2 = vcombine_u8(vld1_u8(u - 3 * stride), vld1_u8(v - 3 * stride));
  *p1 = vcombine_u8(vld1_u8(u - 2 * stride), vld1_u8(v - 2 * stride));
  *p0 = vcombine_u8(vld1_u8(u - 1 * stride), vld1_u8(v - 1 * stride));
  *q0 = vcombine_u8(vld1_u8(u + 0 * stride), vld1_u8(v + 0 * stride));
  *q1 = vcombine_u8(vld1_u8(u + 1 * stride), vld1_u8(v + 1 * stride));
  *q2 = vcombine_u8(vld1_u8(u + 2 * stride), vld1_u8(v + 2 * stride));
  *q3 = vcombine_u8(vld1_u8(u + 3 * stride), vld1_u8(v + 3 * stride));
}

#if !defined(WORK_AROUND_GCC)

#define LOAD_UV_8(ROW) \
  vcombine_u8(vld1_u8(u - 4 + (ROW) * stride), vld1_u8(v - 4 + (ROW) * stride))

static WEBP_INLINE void Load8x8x2T_NEON(
    const uint8_t* const u, const uint8_t* const v, int stride,
    uint8x16_t* const p3, uint8x16_t* const p2, uint8x16_t* const p1,
    uint8x16_t* const p0, uint8x16_t* const q0, uint8x16_t* const q1,
    uint8x16_t* const q2, uint8x16_t* const q3) {
  // We pack the 8x8 u-samples in the lower half of the uint8x16_t destination
  // and the v-samples on the higher half.
  const uint8x16_t row0 = LOAD_UV_8(0);
  const uint8x16_t row1 = LOAD_UV_8(1);
  const uint8x16_t row2 = LOAD_UV_8(2);
  const uint8x16_t row3 = LOAD_UV_8(3);
  const uint8x16_t row4 = LOAD_UV_8(4);
  const uint8x16_t row5 = LOAD_UV_8(5);
  const uint8x16_t row6 = LOAD_UV_8(6);
  const uint8x16_t row7 = LOAD_UV_8(7);
  // Perform two side-by-side 8x8 transposes
  // u00 u01 u02 u03 u04 u05 u06 u07 | v00 v01 v02 v03 v04 v05 v06 v07
  // u10 u11 u12 u13 u14 u15 u16 u17 | v10 v11 v12 ...
  // u20 u21 u22 u23 u24 u25 u26 u27 | v20 v21 ...
  // u30 u31 u32 u33 u34 u35 u36 u37 | ...
  // u40 u41 u42 u43 u44 u45 u46 u47 | ...
  // u50 u51 u52 u53 u54 u55 u56 u57 | ...
  // u60 u61 u62 u63 u64 u65 u66 u67 | v60 ...
  // u70 u71 u72 u73 u74 u75 u76 u77 | v70 v71 v72 ...
  const uint8x16x2_t row01 = vtrnq_u8(row0, row1);  // u00 u10 u02 u12 ...
                                                    // u01 u11 u03 u13 ...
  const uint8x16x2_t row23 = vtrnq_u8(row2, row3);  // u20 u30 u22 u32 ...
                                                    // u21 u31 u23 u33 ...
  const uint8x16x2_t row45 = vtrnq_u8(row4, row5);  // ...
  const uint8x16x2_t row67 = vtrnq_u8(row6, row7);  // ...
  const uint16x8x2_t row02 = vtrnq_u16(vreinterpretq_u16_u8(row01.val[0]),
                                       vreinterpretq_u16_u8(row23.val[0]));
  const uint16x8x2_t row13 = vtrnq_u16(vreinterpretq_u16_u8(row01.val[1]),
                                       vreinterpretq_u16_u8(row23.val[1]));
  const uint16x8x2_t row46 = vtrnq_u16(vreinterpretq_u16_u8(row45.val[0]),
                                       vreinterpretq_u16_u8(row67.val[0]));
  const uint16x8x2_t row57 = vtrnq_u16(vreinterpretq_u16_u8(row45.val[1]),
                                       vreinterpretq_u16_u8(row67.val[1]));
  const uint32x4x2_t row04 = vtrnq_u32(vreinterpretq_u32_u16(row02.val[0]),
                                       vreinterpretq_u32_u16(row46.val[0]));
  const uint32x4x2_t row26 = vtrnq_u32(vreinterpretq_u32_u16(row02.val[1]),
                                       vreinterpretq_u32_u16(row46.val[1]));
  const uint32x4x2_t row15 = vtrnq_u32(vreinterpretq_u32_u16(row13.val[0]),
                                       vreinterpretq_u32_u16(row57.val[0]));
  const uint32x4x2_t row37 = vtrnq_u32(vreinterpretq_u32_u16(row13.val[1]),
                                       vreinterpretq_u32_u16(row57.val[1]));
  *p3 = vreinterpretq_u8_u32(row04.val[0]);
  *p2 = vreinterpretq_u8_u32(row15.val[0]);
  *p1 = vreinterpretq_u8_u32(row26.val[0]);
  *p0 = vreinterpretq_u8_u32(row37.val[0]);
  *q0 = vreinterpretq_u8_u32(row04.val[1]);
  *q1 = vreinterpretq_u8_u32(row15.val[1]);
  *q2 = vreinterpretq_u8_u32(row26.val[1]);
  *q3 = vreinterpretq_u8_u32(row37.val[1]);
}
#undef LOAD_UV_8

#endif  // !WORK_AROUND_GCC

static WEBP_INLINE void Store2x8_NEON(const uint8x8x2_t v,
                                      uint8_t* const dst, int stride) {
  vst2_lane_u8(dst + 0 * stride, v, 0);
  vst2_lane_u8(dst + 1 * stride, v, 1);
  vst2_lane_u8(dst + 2 * stride, v, 2);
  vst2_lane_u8(dst + 3 * stride, v, 3);
  vst2_lane_u8(dst + 4 * stride, v, 4);
  vst2_lane_u8(dst + 5 * stride, v, 5);
  vst2_lane_u8(dst + 6 * stride, v, 6);
  vst2_lane_u8(dst + 7 * stride, v, 7);
}

static WEBP_INLINE void Store2x16_NEON(const uint8x16_t p0, const uint8x16_t q0,
                                       uint8_t* const dst, int stride) {
  uint8x8x2_t lo, hi;
  lo.val[0] = vget_low_u8(p0);
  lo.val[1] = vget_low_u8(q0);
  hi.val[0] = vget_high_u8(p0);
  hi.val[1] = vget_high_u8(q0);
  Store2x8_NEON(lo, dst - 1 + 0 * stride, stride);
  Store2x8_NEON(hi, dst - 1 + 8 * stride, stride);
}

#if !defined(WORK_AROUND_GCC)
static WEBP_INLINE void Store4x8_NEON(const uint8x8x4_t v,
                                      uint8_t* const dst, int stride) {
  vst4_lane_u8(dst + 0 * stride, v, 0);
  vst4_lane_u8(dst + 1 * stride, v, 1);
  vst4_lane_u8(dst + 2 * stride, v, 2);
  vst4_lane_u8(dst + 3 * stride, v, 3);
  vst4_lane_u8(dst + 4 * stride, v, 4);
  vst4_lane_u8(dst + 5 * stride, v, 5);
  vst4_lane_u8(dst + 6 * stride, v, 6);
  vst4_lane_u8(dst + 7 * stride, v, 7);
}

static WEBP_INLINE void Store4x16_NEON(const uint8x16_t p1, const uint8x16_t p0,
                                       const uint8x16_t q0, const uint8x16_t q1,
                                       uint8_t* const dst, int stride) {
  uint8x8x4_t lo, hi;
  INIT_VECTOR4(lo,
               vget_low_u8(p1), vget_low_u8(p0),
               vget_low_u8(q0), vget_low_u8(q1));
  INIT_VECTOR4(hi,
               vget_high_u8(p1), vget_high_u8(p0),
               vget_high_u8(q0), vget_high_u8(q1));
  Store4x8_NEON(lo, dst - 2 + 0 * stride, stride);
  Store4x8_NEON(hi, dst - 2 + 8 * stride, stride);
}
#endif  // !WORK_AROUND_GCC

static WEBP_INLINE void Store16x2_NEON(const uint8x16_t p0, const uint8x16_t q0,
                                       uint8_t* const dst, int stride) {
  vst1q_u8(dst - stride, p0);
  vst1q_u8(dst, q0);
}

static WEBP_INLINE void Store16x4_NEON(const uint8x16_t p1, const uint8x16_t p0,
                                       const uint8x16_t q0, const uint8x16_t q1,
                                       uint8_t* const dst, int stride) {
  Store16x2_NEON(p1, p0, dst - stride, stride);
  Store16x2_NEON(q0, q1, dst + stride, stride);
}

static WEBP_INLINE void Store8x2x2_NEON(const uint8x16_t p0,
                                        const uint8x16_t q0,
                                        uint8_t* const u, uint8_t* const v,
                                        int stride) {
  // p0 and q0 contain the u+v samples packed in low/high halves.
  vst1_u8(u - stride, vget_low_u8(p0));
  vst1_u8(u,          vget_low_u8(q0));
  vst1_u8(v - stride, vget_high_u8(p0));
  vst1_u8(v,          vget_high_u8(q0));
}

static WEBP_INLINE void Store8x4x2_NEON(const uint8x16_t p1,
                                        const uint8x16_t p0,
                                        const uint8x16_t q0,
                                        const uint8x16_t q1,
                                        uint8_t* const u, uint8_t* const v,
                                        int stride) {
  // The p1...q1 registers contain the u+v samples packed in low/high halves.
  Store8x2x2_NEON(p1, p0, u - stride, v - stride, stride);
  Store8x2x2_NEON(q0, q1, u + stride, v + stride, stride);
}

#if !defined(WORK_AROUND_GCC)

#define STORE6_LANE(DST, VAL0, VAL1, LANE) do {   \
  vst3_lane_u8((DST) - 3, (VAL0), (LANE));        \
  vst3_lane_u8((DST) + 0, (VAL1), (LANE));        \
  (DST) += stride;                                \
} while (0)

static WEBP_INLINE void Store6x8x2_NEON(
    const uint8x16_t p2, const uint8x16_t p1, const uint8x16_t p0,
    const uint8x16_t q0, const uint8x16_t q1, const uint8x16_t q2,
    uint8_t* u, uint8_t* v, int stride) {
  uint8x8x3_t u0, u1, v0, v1;
  INIT_VECTOR3(u0, vget_low_u8(p2), vget_low_u8(p1), vget_low_u8(p0));
  INIT_VECTOR3(u1, vget_low_u8(q0), vget_low_u8(q1), vget_low_u8(q2));
  INIT_VECTOR3(v0, vget_high_u8(p2), vget_high_u8(p1), vget_high_u8(p0));
  INIT_VECTOR3(v1, vget_high_u8(q0), vget_high_u8(q1), vget_high_u8(q2));
  STORE6_LANE(u, u0, u1, 0);
  STORE6_LANE(u, u0, u1, 1);
  STORE6_LANE(u, u0, u1, 2);
  STORE6_LANE(u, u0, u1, 3);
  STORE6_LANE(u, u0, u1, 4);
  STORE6_LANE(u, u0, u1, 5);
  STORE6_LANE(u, u0, u1, 6);
  STORE6_LANE(u, u0, u1, 7);
  STORE6_LANE(v, v0, v1, 0);
  STORE6_LANE(v, v0, v1, 1);
  STORE6_LANE(v, v0, v1, 2);
  STORE6_LANE(v, v0, v1, 3);
  STORE6_LANE(v, v0, v1, 4);
  STORE6_LANE(v, v0, v1, 5);
  STORE6_LANE(v, v0, v1, 6);
  STORE6_LANE(v, v0, v1, 7);
}
#undef STORE6_LANE

static WEBP_INLINE void Store4x8x2_NEON(const uint8x16_t p1,
                                        const uint8x16_t p0,
                                        const uint8x16_t q0,
                                        const uint8x16_t q1,
                                        uint8_t* const u, uint8_t* const v,
                                        int stride) {
  uint8x8x4_t u0, v0;
  INIT_VECTOR4(u0,
               vget_low_u8(p1), vget_low_u8(p0),
               vget_low_u8(q0), vget_low_u8(q1));
  INIT_VECTOR4(v0,
               vget_high_u8(p1), vget_high_u8(p0),
               vget_high_u8(q0), vget_high_u8(q1));
  vst4_lane_u8(u - 2 + 0 * stride, u0, 0);
  vst4_lane_u8(u - 2 + 1 * stride, u0, 1);
  vst4_lane_u8(u - 2 + 2 * stride, u0, 2);
  vst4_lane_u8(u - 2 + 3 * stride, u0, 3);
  vst4_lane_u8(u - 2 + 4 * stride, u0, 4);
  vst4_lane_u8(u - 2 + 5 * stride, u0, 5);
  vst4_lane_u8(u - 2 + 6 * stride, u0, 6);
  vst4_lane_u8(u - 2 + 7 * stride, u0, 7);
  vst4_lane_u8(v - 2 + 0 * stride, v0, 0);
  vst4_lane_u8(v - 2 + 1 * stride, v0, 1);
  vst4_lane_u8(v - 2 + 2 * stride, v0, 2);
  vst4_lane_u8(v - 2 + 3 * stride, v0, 3);
  vst4_lane_u8(v - 2 + 4 * stride, v0, 4);
  vst4_lane_u8(v - 2 + 5 * stride, v0, 5);
  vst4_lane_u8(v - 2 + 6 * stride, v0, 6);
  vst4_lane_u8(v - 2 + 7 * stride, v0, 7);
}

#endif  // !WORK_AROUND_GCC

// Zero extend 'v' to an int16x8_t.
static WEBP_INLINE int16x8_t ConvertU8ToS16_NEON(uint8x8_t v) {
  return vreinterpretq_s16_u16(vmovl_u8(v));
}

// Performs unsigned 8b saturation on 'dst01' and 'dst23' storing the result
// to the corresponding rows of 'dst'.
static WEBP_INLINE void SaturateAndStore4x4_NEON(uint8_t* const dst,
                                                 const int16x8_t dst01,
                                                 const int16x8_t dst23) {
  // Unsigned saturate to 8b.
  const uint8x8_t dst01_u8 = vqmovun_s16(dst01);
  const uint8x8_t dst23_u8 = vqmovun_s16(dst23);

  // Store the results.
  vst1_lane_u32((uint32_t*)(dst + 0 * BPS), vreinterpret_u32_u8(dst01_u8), 0);
  vst1_lane_u32((uint32_t*)(dst + 1 * BPS), vreinterpret_u32_u8(dst01_u8), 1);
  vst1_lane_u32((uint32_t*)(dst + 2 * BPS), vreinterpret_u32_u8(dst23_u8), 0);
  vst1_lane_u32((uint32_t*)(dst + 3 * BPS), vreinterpret_u32_u8(dst23_u8), 1);
}

static WEBP_INLINE void Add4x4_NEON(const int16x8_t row01,
                                    const int16x8_t row23,
                                    uint8_t* const dst) {
  uint32x2_t dst01 = vdup_n_u32(0);
  uint32x2_t dst23 = vdup_n_u32(0);

  // Load the source pixels.
  dst01 = vld1_lane_u32((uint32_t*)(dst + 0 * BPS), dst01, 0);
  dst23 = vld1_lane_u32((uint32_t*)(dst + 2 * BPS), dst23, 0);
  dst01 = vld1_lane_u32((uint32_t*)(dst + 1 * BPS), dst01, 1);
  dst23 = vld1_lane_u32((uint32_t*)(dst + 3 * BPS), dst23, 1);

  {
    // Convert to 16b.
    const int16x8_t dst01_s16 = ConvertU8ToS16_NEON(vreinterpret_u8_u32(dst01));
    const int16x8_t dst23_s16 = ConvertU8ToS16_NEON(vreinterpret_u8_u32(dst23));

    // Descale with rounding.
    const int16x8_t out01 = vrsraq_n_s16(dst01_s16, row01, 3);
    const int16x8_t out23 = vrsraq_n_s16(dst23_s16, row23, 3);
    // Add the inverse transform.
    SaturateAndStore4x4_NEON(dst, out01, out23);
  }
}

//-----------------------------------------------------------------------------
// Simple In-loop filtering (Paragraph 15.2)

static uint8x16_t NeedsFilter_NEON(const uint8x16_t p1, const uint8x16_t p0,
                                   const uint8x16_t q0, const uint8x16_t q1,
                                   int thresh) {
  const uint8x16_t thresh_v = vdupq_n_u8((uint8_t)thresh);
  const uint8x16_t a_p0_q0 = vabdq_u8(p0, q0);               // abs(p0-q0)
  const uint8x16_t a_p1_q1 = vabdq_u8(p1, q1);               // abs(p1-q1)
  const uint8x16_t a_p0_q0_2 = vqaddq_u8(a_p0_q0, a_p0_q0);  // 2 * abs(p0-q0)
  const uint8x16_t a_p1_q1_2 = vshrq_n_u8(a_p1_q1, 1);       // abs(p1-q1) / 2
  const uint8x16_t sum = vqaddq_u8(a_p0_q0_2, a_p1_q1_2);
  const uint8x16_t mask = vcgeq_u8(thresh_v, sum);
  return mask;
}

static int8x16_t FlipSign_NEON(const uint8x16_t v) {
  const uint8x16_t sign_bit = vdupq_n_u8(0x80);
  return vreinterpretq_s8_u8(veorq_u8(v, sign_bit));
}

static uint8x16_t FlipSignBack_NEON(const int8x16_t v) {
  const int8x16_t sign_bit = vdupq_n_s8(0x80);
  return vreinterpretq_u8_s8(veorq_s8(v, sign_bit));
}

static int8x16_t GetBaseDelta_NEON(const int8x16_t p1, const int8x16_t p0,
                                   const int8x16_t q0, const int8x16_t q1) {
  const int8x16_t q0_p0 = vqsubq_s8(q0, p0);      // (q0-p0)
  const int8x16_t p1_q1 = vqsubq_s8(p1, q1);      // (p1-q1)
  const int8x16_t s1 = vqaddq_s8(p1_q1, q0_p0);   // (p1-q1) + 1 * (q0 - p0)
  const int8x16_t s2 = vqaddq_s8(q0_p0, s1);      // (p1-q1) + 2 * (q0 - p0)
  const int8x16_t s3 = vqaddq_s8(q0_p0, s2);      // (p1-q1) + 3 * (q0 - p0)
  return s3;
}

static int8x16_t GetBaseDelta0_NEON(const int8x16_t p0, const int8x16_t q0) {
  const int8x16_t q0_p0 = vqsubq_s8(q0, p0);      // (q0-p0)
  const int8x16_t s1 = vqaddq_s8(q0_p0, q0_p0);   // 2 * (q0 - p0)
  const int8x16_t s2 = vqaddq_s8(q0_p0, s1);      // 3 * (q0 - p0)
  return s2;
}

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

static void ApplyFilter2NoFlip_NEON(const int8x16_t p0s, const int8x16_t q0s,
                                    const int8x16_t delta,
                                    int8x16_t* const op0,
                                    int8x16_t* const oq0) {
  const int8x16_t kCst3 = vdupq_n_s8(0x03);
  const int8x16_t kCst4 = vdupq_n_s8(0x04);
  const int8x16_t delta_p3 = vqaddq_s8(delta, kCst3);
  const int8x16_t delta_p4 = vqaddq_s8(delta, kCst4);
  const int8x16_t delta3 = vshrq_n_s8(delta_p3, 3);
  const int8x16_t delta4 = vshrq_n_s8(delta_p4, 3);
  *op0 = vqaddq_s8(p0s, delta3);
  *oq0 = vqsubq_s8(q0s, delta4);
}

#if defined(WEBP_USE_INTRINSICS)

static void ApplyFilter2_NEON(const int8x16_t p0s, const int8x16_t q0s,
                              const int8x16_t delta,
                              uint8x16_t* const op0, uint8x16_t* const oq0) {
  const int8x16_t kCst3 = vdupq_n_s8(0x03);
  const int8x16_t kCst4 = vdupq_n_s8(0x04);
  const int8x16_t delta_p3 = vqaddq_s8(delta, kCst3);
  const int8x16_t delta_p4 = vqaddq_s8(delta, kCst4);
  const int8x16_t delta3 = vshrq_n_s8(delta_p3, 3);
  const int8x16_t delta4 = vshrq_n_s8(delta_p4, 3);
  const int8x16_t sp0 = vqaddq_s8(p0s, delta3);
  const int8x16_t sq0 = vqsubq_s8(q0s, delta4);
  *op0 = FlipSignBack_NEON(sp0);
  *oq0 = FlipSignBack_NEON(sq0);
}

static void DoFilter2_NEON(const uint8x16_t p1, const uint8x16_t p0,
                           const uint8x16_t q0, const uint8x16_t q1,
                           const uint8x16_t mask,
                           uint8x16_t* const op0, uint8x16_t* const oq0) {
  const int8x16_t p1s = FlipSign_NEON(p1);
  const int8x16_t p0s = FlipSign_NEON(p0);
  const int8x16_t q0s = FlipSign_NEON(q0);
  const int8x16_t q1s = FlipSign_NEON(q1);
  const int8x16_t delta0 = GetBaseDelta_NEON(p1s, p0s, q0s, q1s);
  const int8x16_t delta1 = vandq_s8(delta0, vreinterpretq_s8_u8(mask));
  ApplyFilter2_NEON(p0s, q0s, delta1, op0, oq0);
}

static void SimpleVFilter16_NEON(uint8_t* p, int stride, int thresh) {
  uint8x16_t p1, p0, q0, q1, op0, oq0;
  Load16x4_NEON(p, stride, &p1, &p0, &q0, &q1);
  {
    const uint8x16_t mask = NeedsFilter_NEON(p1, p0, q0, q1, thresh);
    DoFilter2_NEON(p1, p0, q0, q1, mask, &op0, &oq0);
  }
  Store16x2_NEON(op0, oq0, p, stride);
}

static void SimpleHFilter16_NEON(uint8_t* p, int stride, int thresh) {
  uint8x16_t p1, p0, q0, q1, oq0, op0;
  Load4x16_NEON(p, stride, &p1, &p0, &q0, &q1);
  {
    const uint8x16_t mask = NeedsFilter_NEON(p1, p0, q0, q1, thresh);
    DoFilter2_NEON(p1, p0, q0, q1, mask, &op0, &oq0);
  }
  Store2x16_NEON(op0, oq0, p, stride);
}

#else

// Load/Store vertical edge
#define LOAD8x4(c1, c2, c3, c4, b1, b2, stride)                                \
  "vld4.8 {" #c1 "[0]," #c2 "[0]," #c3 "[0]," #c4 "[0]}," #b1 "," #stride "\n" \
  "vld4.8 {" #c1 "[1]," #c2 "[1]," #c3 "[1]," #c4 "[1]}," #b2 "," #stride "\n" \
  "vld4.8 {" #c1 "[2]," #c2 "[2]," #c3 "[2]," #c4 "[2]}," #b1 "," #stride "\n" \
  "vld4.8 {" #c1 "[3]," #c2 "[3]," #c3 "[3]," #c4 "[3]}," #b2 "," #stride "\n" \
  "vld4.8 {" #c1 "[4]," #c2 "[4]," #c3 "[4]," #c4 "[4]}," #b1 "," #stride "\n" \
  "vld4.8 {" #c1 "[5]," #c2 "[5]," #c3 "[5]," #c4 "[5]}," #b2 "," #stride "\n" \
  "vld4.8 {" #c1 "[6]," #c2 "[6]," #c3 "[6]," #c4 "[6]}," #b1 "," #stride "\n" \
  "vld4.8 {" #c1 "[7]," #c2 "[7]," #c3 "[7]," #c4 "[7]}," #b2 "," #stride "\n"

#define STORE8x2(c1, c2, p, stride)                                            \
  "vst2.8   {" #c1 "[0], " #c2 "[0]}," #p "," #stride " \n"                    \
  "vst2.8   {" #c1 "[1], " #c2 "[1]}," #p "," #stride " \n"                    \
  "vst2.8   {" #c1 "[2], " #c2 "[2]}," #p "," #stride " \n"                    \
  "vst2.8   {" #c1 "[3], " #c2 "[3]}," #p "," #stride " \n"                    \
  "vst2.8   {" #c1 "[4], " #c2 "[4]}," #p "," #stride " \n"                    \
  "vst2.8   {" #c1 "[5], " #c2 "[5]}," #p "," #stride " \n"                    \
  "vst2.8   {" #c1 "[6], " #c2 "[6]}," #p "," #stride " \n"                    \
  "vst2.8   {" #c1 "[7], " #c2 "[7]}," #p "," #stride " \n"

#define QRegs "q0", "q1", "q2", "q3",                                          \
              "q8", "q9", "q10", "q11", "q12", "q13", "q14", "q15"

#define FLIP_SIGN_BIT2(a, b, s)                                                \
  "veor     " #a "," #a "," #s "               \n"                             \
  "veor     " #b "," #b "," #s "               \n"                             \

#define FLIP_SIGN_BIT4(a, b, c, d, s)                                          \
  FLIP_SIGN_BIT2(a, b, s)                                                      \
  FLIP_SIGN_BIT2(c, d, s)                                                      \

#define NEEDS_FILTER(p1, p0, q0, q1, thresh, mask)                             \
  "vabd.u8    q15," #p0 "," #q0 "         \n"  /* abs(p0 - q0) */              \
  "vabd.u8    q14," #p1 "," #q1 "         \n"  /* abs(p1 - q1) */              \
  "vqadd.u8   q15, q15, q15               \n"  /* abs(p0 - q0) * 2 */          \
  "vshr.u8    q14, q14, #1                \n"  /* abs(p1 - q1) / 2 */          \
  "vqadd.u8   q15, q15, q14     \n"  /* abs(p0 - q0) * 2 + abs(p1 - q1) / 2 */ \
  "vdup.8     q14, " #thresh "            \n"                                  \
  "vcge.u8   " #mask ", q14, q15          \n"  /* mask <= thresh */

#define GET_BASE_DELTA(p1, p0, q0, q1, o)                                      \
  "vqsub.s8   q15," #q0 "," #p0 "         \n"  /* (q0 - p0) */                 \
  "vqsub.s8  " #o "," #p1 "," #q1 "       \n"  /* (p1 - q1) */                 \
  "vqadd.s8  " #o "," #o ", q15           \n"  /* (p1 - q1) + 1 * (p0 - q0) */ \
  "vqadd.s8  " #o "," #o ", q15           \n"  /* (p1 - q1) + 2 * (p0 - q0) */ \
  "vqadd.s8  " #o "," #o ", q15           \n"  /* (p1 - q1) + 3 * (p0 - q0) */

#define DO_SIMPLE_FILTER(p0, q0, fl)                                           \
  "vmov.i8    q15, #0x03                  \n"                                  \
  "vqadd.s8   q15, q15, " #fl "           \n"  /* filter1 = filter + 3 */      \
  "vshr.s8    q15, q15, #3                \n"  /* filter1 >> 3 */              \
  "vqadd.s8  " #p0 "," #p0 ", q15         \n"  /* p0 += filter1 */             \
                                                                               \
  "vmov.i8    q15, #0x04                  \n"                                  \
  "vqadd.s8   q15, q15, " #fl "           \n"  /* filter1 = filter + 4 */      \
  "vshr.s8    q15, q15, #3                \n"  /* filter2 >> 3 */              \
  "vqsub.s8  " #q0 "," #q0 ", q15         \n"  /* q0 -= filter2 */

// Applies filter on 2 pixels (p0 and q0)
#define DO_FILTER2(p1, p0, q0, q1, thresh)                                     \
  NEEDS_FILTER(p1, p0, q0, q1, thresh, q9)     /* filter mask in q9 */         \
  "vmov.i8    q10, #0x80                  \n"  /* sign bit */                  \
  FLIP_SIGN_BIT4(p1, p0, q0, q1, q10)          /* convert to signed value */   \
  GET_BASE_DELTA(p1, p0, q0, q1, q11)          /* get filter level  */         \
  "vand       q9, q9, q11                 \n"  /* apply filter mask */         \
  DO_SIMPLE_FILTER(p0, q0, q9)                 /* apply filter */              \
  FLIP_SIGN_BIT2(p0, q0, q10)

static void SimpleVFilter16_NEON(uint8_t* p, int stride, int thresh) {
  __asm__ volatile (
    "sub        %[p], %[p], %[stride], lsl #1  \n"  // p -= 2 * stride

    "vld1.u8    {q1}, [%[p]], %[stride]        \n"  // p1
    "vld1.u8    {q2}, [%[p]], %[stride]        \n"  // p0
    "vld1.u8    {q3}, [%[p]], %[stride]        \n"  // q0
    "vld1.u8    {q12}, [%[p]]                  \n"  // q1

    DO_FILTER2(q1, q2, q3, q12, %[thresh])

    "sub        %[p], %[p], %[stride], lsl #1  \n"  // p -= 2 * stride

    "vst1.u8    {q2}, [%[p]], %[stride]        \n"  // store op0
    "vst1.u8    {q3}, [%[p]]                   \n"  // store oq0
    : [p] "+r"(p)
    : [stride] "r"(stride), [thresh] "r"(thresh)
    : "memory", QRegs
  );
}

static void SimpleHFilter16_NEON(uint8_t* p, int stride, int thresh) {
  __asm__ volatile (
    "sub        r4, %[p], #2                   \n"  // base1 = p - 2
    "lsl        r6, %[stride], #1              \n"  // r6 = 2 * stride
    "add        r5, r4, %[stride]              \n"  // base2 = base1 + stride

    LOAD8x4(d2, d3, d4, d5, [r4], [r5], r6)
    LOAD8x4(d24, d25, d26, d27, [r4], [r5], r6)
    "vswp       d3, d24                        \n"  // p1:q1 p0:q3
    "vswp       d5, d26                        \n"  // q0:q2 q1:q4
    "vswp       q2, q12                        \n"  // p1:q1 p0:q2 q0:q3 q1:q4

    DO_FILTER2(q1, q2, q12, q13, %[thresh])

    "sub        %[p], %[p], #1                 \n"  // p - 1

    "vswp        d5, d24                       \n"
    STORE8x2(d4, d5, [%[p]], %[stride])
    STORE8x2(d24, d25, [%[p]], %[stride])

    : [p] "+r"(p)
    : [stride] "r"(stride), [thresh] "r"(thresh)
    : "memory", "r4", "r5", "r6", QRegs
  );
}

#undef LOAD8x4
#undef STORE8x2

#endif    // WEBP_USE_INTRINSICS

static void SimpleVFilter16i_NEON(uint8_t* p, int stride, int thresh) {
  uint32_t k;
  for (k = 3; k != 0; --k) {
    p += 4 * stride;
    SimpleVFilter16_NEON(p, stride, thresh);
  }
}

static void SimpleHFilter16i_NEON(uint8_t* p, int stride, int thresh) {
  uint32_t k;
  for (k = 3; k != 0; --k) {
    p += 4;
    SimpleHFilter16_NEON(p, stride, thresh);
  }
}

//------------------------------------------------------------------------------
// Complex In-loop filtering (Paragraph 15.3)

static uint8x16_t NeedsHev_NEON(const uint8x16_t p1, const uint8x16_t p0,
                                const uint8x16_t q0, const uint8x16_t q1,
                                int hev_thresh) {
  const uint8x16_t hev_thresh_v = vdupq_n_u8((uint8_t)hev_thresh);
  const uint8x16_t a_p1_p0 = vabdq_u8(p1, p0);  // abs(p1 - p0)
  const uint8x16_t a_q1_q0 = vabdq_u8(q1, q0);  // abs(q1 - q0)
  const uint8x16_t a_max = vmaxq_u8(a_p1_p0, a_q1_q0);
  const uint8x16_t mask = vcgtq_u8(a_max, hev_thresh_v);
  return mask;
}

static uint8x16_t NeedsFilter2_NEON(const uint8x16_t p3, const uint8x16_t p2,
                                    const uint8x16_t p1, const uint8x16_t p0,
                                    const uint8x16_t q0, const uint8x16_t q1,
                                    const uint8x16_t q2, const uint8x16_t q3,
                                    int ithresh, int thresh) {
  const uint8x16_t ithresh_v = vdupq_n_u8((uint8_t)ithresh);
  const uint8x16_t a_p3_p2 = vabdq_u8(p3, p2);  // abs(p3 - p2)
  const uint8x16_t a_p2_p1 = vabdq_u8(p2, p1);  // abs(p2 - p1)
  const uint8x16_t a_p1_p0 = vabdq_u8(p1, p0);  // abs(p1 - p0)
  const uint8x16_t a_q3_q2 = vabdq_u8(q3, q2);  // abs(q3 - q2)
  const uint8x16_t a_q2_q1 = vabdq_u8(q2, q1);  // abs(q2 - q1)
  const uint8x16_t a_q1_q0 = vabdq_u8(q1, q0);  // abs(q1 - q0)
  const uint8x16_t max1 = vmaxq_u8(a_p3_p2, a_p2_p1);
  const uint8x16_t max2 = vmaxq_u8(a_p1_p0, a_q3_q2);
  const uint8x16_t max3 = vmaxq_u8(a_q2_q1, a_q1_q0);
  const uint8x16_t max12 = vmaxq_u8(max1, max2);
  const uint8x16_t max123 = vmaxq_u8(max12, max3);
  const uint8x16_t mask2 = vcgeq_u8(ithresh_v, max123);
  const uint8x16_t mask1 = NeedsFilter_NEON(p1, p0, q0, q1, thresh);
  const uint8x16_t mask = vandq_u8(mask1, mask2);
  return mask;
}

//  4-points filter

static void ApplyFilter4_NEON(
    const int8x16_t p1, const int8x16_t p0,
    const int8x16_t q0, const int8x16_t q1,
    const int8x16_t delta0,
    uint8x16_t* const op1, uint8x16_t* const op0,
    uint8x16_t* const oq0, uint8x16_t* const oq1) {
  const int8x16_t kCst3 = vdupq_n_s8(0x03);
  const int8x16_t kCst4 = vdupq_n_s8(0x04);
  const int8x16_t delta1 = vqaddq_s8(delta0, kCst4);
  const int8x16_t delta2 = vqaddq_s8(delta0, kCst3);
  const int8x16_t a1 = vshrq_n_s8(delta1, 3);
  const int8x16_t a2 = vshrq_n_s8(delta2, 3);
  const int8x16_t a3 = vrshrq_n_s8(a1, 1);   // a3 = (a1 + 1) >> 1
  *op0 = FlipSignBack_NEON(vqaddq_s8(p0, a2));  // clip(p0 + a2)
  *oq0 = FlipSignBack_NEON(vqsubq_s8(q0, a1));  // clip(q0 - a1)
  *op1 = FlipSignBack_NEON(vqaddq_s8(p1, a3));  // clip(p1 + a3)
  *oq1 = FlipSignBack_NEON(vqsubq_s8(q1, a3));  // clip(q1 - a3)
}

static void DoFilter4_NEON(
    const uint8x16_t p1, const uint8x16_t p0,
    const uint8x16_t q0, const uint8x16_t q1,
    const uint8x16_t mask, const uint8x16_t hev_mask,
    uint8x16_t* const op1, uint8x16_t* const op0,
    uint8x16_t* const oq0, uint8x16_t* const oq1) {
  // This is a fused version of DoFilter2() calling ApplyFilter2 directly
  const int8x16_t p1s = FlipSign_NEON(p1);
  int8x16_t p0s = FlipSign_NEON(p0);
  int8x16_t q0s = FlipSign_NEON(q0);
  const int8x16_t q1s = FlipSign_NEON(q1);
  const uint8x16_t simple_lf_mask = vandq_u8(mask, hev_mask);

  // do_filter2 part (simple loopfilter on pixels with hev)
  {
    const int8x16_t delta = GetBaseDelta_NEON(p1s, p0s, q0s, q1s);
    const int8x16_t simple_lf_delta =
        vandq_s8(delta, vreinterpretq_s8_u8(simple_lf_mask));
    ApplyFilter2NoFlip_NEON(p0s, q0s, simple_lf_delta, &p0s, &q0s);
  }

  // do_filter4 part (complex loopfilter on pixels without hev)
  {
    const int8x16_t delta0 = GetBaseDelta0_NEON(p0s, q0s);
    // we use: (mask & hev_mask) ^ mask = mask & !hev_mask
    const uint8x16_t complex_lf_mask = veorq_u8(simple_lf_mask, mask);
    const int8x16_t complex_lf_delta =
        vandq_s8(delta0, vreinterpretq_s8_u8(complex_lf_mask));
    ApplyFilter4_NEON(p1s, p0s, q0s, q1s, complex_lf_delta, op1, op0, oq0, oq1);
  }
}

//  6-points filter

static void ApplyFilter6_NEON(
    const int8x16_t p2, const int8x16_t p1, const int8x16_t p0,
    const int8x16_t q0, const int8x16_t q1, const int8x16_t q2,
    const int8x16_t delta,
    uint8x16_t* const op2, uint8x16_t* const op1, uint8x16_t* const op0,
    uint8x16_t* const oq0, uint8x16_t* const oq1, uint8x16_t* const oq2) {
  // We have to compute: X = (9*a+63) >> 7, Y = (18*a+63)>>7, Z = (27*a+63) >> 7
  // Turns out, there's a common sub-expression S=9 * a - 1 that can be used
  // with the special vqrshrn_n_s16 rounding-shift-and-narrow instruction:
  //   X = (S + 64) >> 7, Y = (S + 32) >> 6, Z = (18 * a + S + 64) >> 7
  const int8x8_t delta_lo = vget_low_s8(delta);
  const int8x8_t delta_hi = vget_high_s8(delta);
  const int8x8_t kCst9 = vdup_n_s8(9);
  const int16x8_t kCstm1 = vdupq_n_s16(-1);
  const int8x8_t kCst18 = vdup_n_s8(18);
  const int16x8_t S_lo = vmlal_s8(kCstm1, kCst9, delta_lo);  // S = 9 * a - 1
  const int16x8_t S_hi = vmlal_s8(kCstm1, kCst9, delta_hi);
  const int16x8_t Z_lo = vmlal_s8(S_lo, kCst18, delta_lo);   // S + 18 * a
  const int16x8_t Z_hi = vmlal_s8(S_hi, kCst18, delta_hi);
  const int8x8_t a3_lo = vqrshrn_n_s16(S_lo, 7);   // (9 * a + 63) >> 7
  const int8x8_t a3_hi = vqrshrn_n_s16(S_hi, 7);
  const int8x8_t a2_lo = vqrshrn_n_s16(S_lo, 6);   // (9 * a + 31) >> 6
  const int8x8_t a2_hi = vqrshrn_n_s16(S_hi, 6);
  const int8x8_t a1_lo = vqrshrn_n_s16(Z_lo, 7);   // (27 * a + 63) >> 7
  const int8x8_t a1_hi = vqrshrn_n_s16(Z_hi, 7);
  const int8x16_t a1 = vcombine_s8(a1_lo, a1_hi);
  const int8x16_t a2 = vcombine_s8(a2_lo, a2_hi);
  const int8x16_t a3 = vcombine_s8(a3_lo, a3_hi);

  *op0 = FlipSignBack_NEON(vqaddq_s8(p0, a1));  // clip(p0 + a1)
  *oq0 = FlipSignBack_NEON(vqsubq_s8(q0, a1));  // clip(q0 - q1)
  *oq1 = FlipSignBack_NEON(vqsubq_s8(q1, a2));  // clip(q1 - a2)
  *op1 = FlipSignBack_NEON(vqaddq_s8(p1, a2));  // clip(p1 + a2)
  *oq2 = FlipSignBack_NEON(vqsubq_s8(q2, a3));  // clip(q2 - a3)
  *op2 = FlipSignBack_NEON(vqaddq_s8(p2, a3));  // clip(p2 + a3)
}

static void DoFilter6_NEON(
    const uint8x16_t p2, const uint8x16_t p1, const uint8x16_t p0,
    const uint8x16_t q0, const uint8x16_t q1, const uint8x16_t q2,
    const uint8x16_t mask, const uint8x16_t hev_mask,
    uint8x16_t* const op2, uint8x16_t* const op1, uint8x16_t* const op0,
    uint8x16_t* const oq0, uint8x16_t* const oq1, uint8x16_t* const oq2) {
  // This is a fused version of DoFilter2() calling ApplyFilter2 directly
  const int8x16_t p2s = FlipSign_NEON(p2);
  const int8x16_t p1s = FlipSign_NEON(p1);
  int8x16_t p0s = FlipSign_NEON(p0);
  int8x16_t q0s = FlipSign_NEON(q0);
  const int8x16_t q1s = FlipSign_NEON(q1);
  const int8x16_t q2s = FlipSign_NEON(q2);
  const uint8x16_t simple_lf_mask = vandq_u8(mask, hev_mask);
  const int8x16_t delta0 = GetBaseDelta_NEON(p1s, p0s, q0s, q1s);

  // do_filter2 part (simple loopfilter on pixels with hev)
  {
    const int8x16_t simple_lf_delta =
        vandq_s8(delta0, vreinterpretq_s8_u8(simple_lf_mask));
    ApplyFilter2NoFlip_NEON(p0s, q0s, simple_lf_delta, &p0s, &q0s);
  }

  // do_filter6 part (complex loopfilter on pixels without hev)
  {
    // we use: (mask & hev_mask) ^ mask = mask & !hev_mask
    const uint8x16_t complex_lf_mask = veorq_u8(simple_lf_mask, mask);
    const int8x16_t complex_lf_delta =
        vandq_s8(delta0, vreinterpretq_s8_u8(complex_lf_mask));
    ApplyFilter6_NEON(p2s, p1s, p0s, q0s, q1s, q2s, complex_lf_delta,
                      op2, op1, op0, oq0, oq1, oq2);
  }
}

// on macroblock edges

static void VFilter16_NEON(uint8_t* p, int stride,
                           int thresh, int ithresh, int hev_thresh) {
  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
  Load16x8_NEON(p, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
  {
    const uint8x16_t mask = NeedsFilter2_NEON(p3, p2, p1, p0, q0, q1, q2, q3,
                                              ithresh, thresh);
    const uint8x16_t hev_mask = NeedsHev_NEON(p1, p0, q0, q1, hev_thresh);
    uint8x16_t op2, op1, op0, oq0, oq1, oq2;
    DoFilter6_NEON(p2, p1, p0, q0, q1, q2, mask, hev_mask,
                   &op2, &op1, &op0, &oq0, &oq1, &oq2);
    Store16x2_NEON(op2, op1, p - 2 * stride, stride);
    Store16x2_NEON(op0, oq0, p + 0 * stride, stride);
    Store16x2_NEON(oq1, oq2, p + 2 * stride, stride);
  }
}

static void HFilter16_NEON(uint8_t* p, int stride,
                           int thresh, int ithresh, int hev_thresh) {
  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
  Load8x16_NEON(p, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
  {
    const uint8x16_t mask = NeedsFilter2_NEON(p3, p2, p1, p0, q0, q1, q2, q3,
                                              ithresh, thresh);
    const uint8x16_t hev_mask = NeedsHev_NEON(p1, p0, q0, q1, hev_thresh);
    uint8x16_t op2, op1, op0, oq0, oq1, oq2;
    DoFilter6_NEON(p2, p1, p0, q0, q1, q2, mask, hev_mask,
                   &op2, &op1, &op0, &oq0, &oq1, &oq2);
    Store2x16_NEON(op2, op1, p - 2, stride);
    Store2x16_NEON(op0, oq0, p + 0, stride);
    Store2x16_NEON(oq1, oq2, p + 2, stride);
  }
}

// on three inner edges
static void VFilter16i_NEON(uint8_t* p, int stride,
                            int thresh, int ithresh, int hev_thresh) {
  uint32_t k;
  uint8x16_t p3, p2, p1, p0;
  Load16x4_NEON(p + 2  * stride, stride, &p3, &p2, &p1, &p0);
  for (k = 3; k != 0; --k) {
    uint8x16_t q0, q1, q2, q3;
    p += 4 * stride;
    Load16x4_NEON(p + 2  * stride, stride, &q0, &q1, &q2, &q3);
    {
      const uint8x16_t mask =
          NeedsFilter2_NEON(p3, p2, p1, p0, q0, q1, q2, q3, ithresh, thresh);
      const uint8x16_t hev_mask = NeedsHev_NEON(p1, p0, q0, q1, hev_thresh);
      // p3 and p2 are not just temporary variables here: they will be
      // re-used for next span. And q2/q3 will become p1/p0 accordingly.
      DoFilter4_NEON(p1, p0, q0, q1, mask, hev_mask, &p1, &p0, &p3, &p2);
      Store16x4_NEON(p1, p0, p3, p2, p, stride);
      p1 = q2;
      p0 = q3;
    }
  }
}

#if !defined(WORK_AROUND_GCC)
static void HFilter16i_NEON(uint8_t* p, int stride,
                            int thresh, int ithresh, int hev_thresh) {
  uint32_t k;
  uint8x16_t p3, p2, p1, p0;
  Load4x16_NEON(p + 2, stride, &p3, &p2, &p1, &p0);
  for (k = 3; k != 0; --k) {
    uint8x16_t q0, q1, q2, q3;
    p += 4;
    Load4x16_NEON(p + 2, stride, &q0, &q1, &q2, &q3);
    {
      const uint8x16_t mask =
          NeedsFilter2_NEON(p3, p2, p1, p0, q0, q1, q2, q3, ithresh, thresh);
      const uint8x16_t hev_mask = NeedsHev_NEON(p1, p0, q0, q1, hev_thresh);
      DoFilter4_NEON(p1, p0, q0, q1, mask, hev_mask, &p1, &p0, &p3, &p2);
      Store4x16_NEON(p1, p0, p3, p2, p, stride);
      p1 = q2;
      p0 = q3;
    }
  }
}
#endif  // !WORK_AROUND_GCC

// 8-pixels wide variant, for chroma filtering
static void VFilter8_NEON(uint8_t* u, uint8_t* v, int stride,
                          int thresh, int ithresh, int hev_thresh) {
  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
  Load8x8x2_NEON(u, v, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
  {
    const uint8x16_t mask = NeedsFilter2_NEON(p3, p2, p1, p0, q0, q1, q2, q3,
                                              ithresh, thresh);
    const uint8x16_t hev_mask = NeedsHev_NEON(p1, p0, q0, q1, hev_thresh);
    uint8x16_t op2, op1, op0, oq0, oq1, oq2;
    DoFilter6_NEON(p2, p1, p0, q0, q1, q2, mask, hev_mask,
                   &op2, &op1, &op0, &oq0, &oq1, &oq2);
    Store8x2x2_NEON(op2, op1, u - 2 * stride, v - 2 * stride, stride);
    Store8x2x2_NEON(op0, oq0, u + 0 * stride, v + 0 * stride, stride);
    Store8x2x2_NEON(oq1, oq2, u + 2 * stride, v + 2 * stride, stride);
  }
}
static void VFilter8i_NEON(uint8_t* u, uint8_t* v, int stride,
                           int thresh, int ithresh, int hev_thresh) {
  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
  u += 4 * stride;
  v += 4 * stride;
  Load8x8x2_NEON(u, v, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
  {
    const uint8x16_t mask = NeedsFilter2_NEON(p3, p2, p1, p0, q0, q1, q2, q3,
                                              ithresh, thresh);
    const uint8x16_t hev_mask = NeedsHev_NEON(p1, p0, q0, q1, hev_thresh);
    uint8x16_t op1, op0, oq0, oq1;
    DoFilter4_NEON(p1, p0, q0, q1, mask, hev_mask, &op1, &op0, &oq0, &oq1);
    Store8x4x2_NEON(op1, op0, oq0, oq1, u, v, stride);
  }
}

#if !defined(WORK_AROUND_GCC)
static void HFilter8_NEON(uint8_t* u, uint8_t* v, int stride,
                          int thresh, int ithresh, int hev_thresh) {
  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
  Load8x8x2T_NEON(u, v, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
  {
    const uint8x16_t mask = NeedsFilter2_NEON(p3, p2, p1, p0, q0, q1, q2, q3,
                                              ithresh, thresh);
    const uint8x16_t hev_mask = NeedsHev_NEON(p1, p0, q0, q1, hev_thresh);
    uint8x16_t op2, op1, op0, oq0, oq1, oq2;
    DoFilter6_NEON(p2, p1, p0, q0, q1, q2, mask, hev_mask,
                   &op2, &op1, &op0, &oq0, &oq1, &oq2);
    Store6x8x2_NEON(op2, op1, op0, oq0, oq1, oq2, u, v, stride);
  }
}

static void HFilter8i_NEON(uint8_t* u, uint8_t* v, int stride,
                           int thresh, int ithresh, int hev_thresh) {
  uint8x16_t p3, p2, p1, p0, q0, q1, q2, q3;
  u += 4;
  v += 4;
  Load8x8x2T_NEON(u, v, stride, &p3, &p2, &p1, &p0, &q0, &q1, &q2, &q3);
  {
    const uint8x16_t mask = NeedsFilter2_NEON(p3, p2, p1, p0, q0, q1, q2, q3,
                                              ithresh, thresh);
    const uint8x16_t hev_mask = NeedsHev_NEON(p1, p0, q0, q1, hev_thresh);
    uint8x16_t op1, op0, oq0, oq1;
    DoFilter4_NEON(p1, p0, q0, q1, mask, hev_mask, &op1, &op0, &oq0, &oq1);
    Store4x8x2_NEON(op1, op0, oq0, oq1, u, v, stride);
  }
}
#endif  // !WORK_AROUND_GCC

//-----------------------------------------------------------------------------
// Inverse transforms (Paragraph 14.4)

// Technically these are unsigned but vqdmulh is only available in signed.
// vqdmulh returns high half (effectively >> 16) but also doubles the value,
// changing the >> 16 to >> 15 and requiring an additional >> 1.
// We use this to our advantage with kC2. The canonical value is 35468.
// However, the high bit is set so treating it as signed will give incorrect
// results. We avoid this by down shifting by 1 here to clear the highest bit.
// Combined with the doubling effect of vqdmulh we get >> 16.
// This can not be applied to kC1 because the lowest bit is set. Down shifting
// the constant would reduce precision.

// libwebp uses a trick to avoid some extra addition that libvpx does.
// Instead of:
// temp2 = ip[12] + ((ip[12] * cospi8sqrt2minus1) >> 16);
// libwebp adds 1 << 16 to cospi8sqrt2minus1 (kC1). However, this causes the
// same issue with kC1 and vqdmulh that we work around by down shifting kC2

static const int16_t kC1 = 20091;
static const int16_t kC2 = 17734;  // half of kC2, actually. See comment above.

#if defined(WEBP_USE_INTRINSICS)
static WEBP_INLINE void Transpose8x2_NEON(const int16x8_t in0,
                                          const int16x8_t in1,
                                          int16x8x2_t* const out) {
  // a0 a1 a2 a3 | b0 b1 b2 b3   => a0 b0 c0 d0 | a1 b1 c1 d1
  // c0 c1 c2 c3 | d0 d1 d2 d3      a2 b2 c2 d2 | a3 b3 c3 d3
  const int16x8x2_t tmp0 = vzipq_s16(in0, in1);   // a0 c0 a1 c1 a2 c2 ...
                                                  // b0 d0 b1 d1 b2 d2 ...
  *out = vzipq_s16(tmp0.val[0], tmp0.val[1]);
}

static WEBP_INLINE void TransformPass_NEON(int16x8x2_t* const rows) {
  // {rows} = in0 | in4
  //          in8 | in12
  // B1 = in4 | in12
  const int16x8_t B1 =
      vcombine_s16(vget_high_s16(rows->val[0]), vget_high_s16(rows->val[1]));
  // C0 = kC1 * in4 | kC1 * in12
  // C1 = kC2 * in4 | kC2 * in12
  const int16x8_t C0 = vsraq_n_s16(B1, vqdmulhq_n_s16(B1, kC1), 1);
  const int16x8_t C1 = vqdmulhq_n_s16(B1, kC2);
  const int16x4_t a = vqadd_s16(vget_low_s16(rows->val[0]),
                                vget_low_s16(rows->val[1]));   // in0 + in8
  const int16x4_t b = vqsub_s16(vget_low_s16(rows->val[0]),
                                vget_low_s16(rows->val[1]));   // in0 - in8
  // c = kC2 * in4 - kC1 * in12
  // d = kC1 * in4 + kC2 * in12
  const int16x4_t c = vqsub_s16(vget_low_s16(C1), vget_high_s16(C0));
  const int16x4_t d = vqadd_s16(vget_low_s16(C0), vget_high_s16(C1));
  const int16x8_t D0 = vcombine_s16(a, b);      // D0 = a | b
  const int16x8_t D1 = vcombine_s16(d, c);      // D1 = d | c
  const int16x8_t E0 = vqaddq_s16(D0, D1);      // a+d | b+c
  const int16x8_t E_tmp = vqsubq_s16(D0, D1);   // a-d | b-c
  const int16x8_t E1 = vcombine_s16(vget_high_s16(E_tmp), vget_low_s16(E_tmp));
  Transpose8x2_NEON(E0, E1, rows);
}

static void TransformOne_NEON(const int16_t* in, uint8_t* dst) {
  int16x8x2_t rows;
  INIT_VECTOR2(rows, vld1q_s16(in + 0), vld1q_s16(in + 8));
  TransformPass_NEON(&rows);
  TransformPass_NEON(&rows);
  Add4x4_NEON(rows.val[0], rows.val[1], dst);
}

#else

static void TransformOne_NEON(const int16_t* in, uint8_t* dst) {
  const int kBPS = BPS;
  // kC1, kC2. Padded because vld1.16 loads 8 bytes
  const int16_t constants[4] = { kC1, kC2, 0, 0 };
  /* Adapted from libvpx: vp8/common/arm/neon/shortidct4x4llm_neon.asm */
  __asm__ volatile (
    "vld1.16         {q1, q2}, [%[in]]           \n"
    "vld1.16         {d0}, [%[constants]]        \n"

    /* d2: in[0]
     * d3: in[8]
     * d4: in[4]
     * d5: in[12]
     */
    "vswp            d3, d4                      \n"

    /* q8 = {in[4], in[12]} * kC1 * 2 >> 16
     * q9 = {in[4], in[12]} * kC2 >> 16
     */
    "vqdmulh.s16     q8, q2, d0[0]               \n"
    "vqdmulh.s16     q9, q2, d0[1]               \n"

    /* d22 = a = in[0] + in[8]
     * d23 = b = in[0] - in[8]
     */
    "vqadd.s16       d22, d2, d3                 \n"
    "vqsub.s16       d23, d2, d3                 \n"

    /* The multiplication should be x * kC1 >> 16
     * However, with vqdmulh we get x * kC1 * 2 >> 16
     * (multiply, double, return high half)
     * We avoided this in kC2 by pre-shifting the constant.
     * q8 = in[4]/[12] * kC1 >> 16
     */
    "vshr.s16        q8, q8, #1                  \n"

    /* Add {in[4], in[12]} back after the multiplication. This is handled by
     * adding 1 << 16 to kC1 in the libwebp C code.
     */
    "vqadd.s16       q8, q2, q8                  \n"

    /* d20 = c = in[4]*kC2 - in[12]*kC1
     * d21 = d = in[4]*kC1 + in[12]*kC2
     */
    "vqsub.s16       d20, d18, d17               \n"
    "vqadd.s16       d21, d19, d16               \n"

    /* d2 = tmp[0] = a + d
     * d3 = tmp[1] = b + c
     * d4 = tmp[2] = b - c
     * d5 = tmp[3] = a - d
     */
    "vqadd.s16       d2, d22, d21                \n"
    "vqadd.s16       d3, d23, d20                \n"
    "vqsub.s16       d4, d23, d20                \n"
    "vqsub.s16       d5, d22, d21                \n"

    "vzip.16         q1, q2                      \n"
    "vzip.16         q1, q2                      \n"

    "vswp            d3, d4                      \n"

    /* q8 = {tmp[4], tmp[12]} * kC1 * 2 >> 16
     * q9 = {tmp[4], tmp[12]} * kC2 >> 16
     */
    "vqdmulh.s16     q8, q2, d0[0]               \n"
    "vqdmulh.s16     q9, q2, d0[1]               \n"

    /* d22 = a = tmp[0] + tmp[8]
     * d23 = b = tmp[0] - tmp[8]
     */
    "vqadd.s16       d22, d2, d3                 \n"
    "vqsub.s16       d23, d2, d3                 \n"

    /* See long winded explanations prior */
    "vshr.s16        q8, q8, #1                  \n"
    "vqadd.s16       q8, q2, q8                  \n"

    /* d20 = c = in[4]*kC2 - in[12]*kC1
     * d21 = d = in[4]*kC1 + in[12]*kC2
     */
    "vqsub.s16       d20, d18, d17               \n"
    "vqadd.s16       d21, d19, d16               \n"

    /* d2 = tmp[0] = a + d
     * d3 = tmp[1] = b + c
     * d4 = tmp[2] = b - c
     * d5 = tmp[3] = a - d
     */
    "vqadd.s16       d2, d22, d21                \n"
    "vqadd.s16       d3, d23, d20                \n"
    "vqsub.s16       d4, d23, d20                \n"
    "vqsub.s16       d5, d22, d21                \n"

    "vld1.32         d6[0], [%[dst]], %[kBPS]    \n"
    "vld1.32         d6[1], [%[dst]], %[kBPS]    \n"
    "vld1.32         d7[0], [%[dst]], %[kBPS]    \n"
    "vld1.32         d7[1], [%[dst]], %[kBPS]    \n"

    "sub         %[dst], %[dst], %[kBPS], lsl #2 \n"

    /* (val) + 4 >> 3 */
    "vrshr.s16       d2, d2, #3                  \n"
    "vrshr.s16       d3, d3, #3                  \n"
    "vrshr.s16       d4, d4, #3                  \n"
    "vrshr.s16       d5, d5, #3                  \n"

    "vzip.16         q1, q2                      \n"
    "vzip.16         q1, q2                      \n"

    /* Must accumulate before saturating */
    "vmovl.u8        q8, d6                      \n"
    "vmovl.u8        q9, d7                      \n"

    "vqadd.s16       q1, q1, q8                  \n"
    "vqadd.s16       q2, q2, q9                  \n"

    "vqmovun.s16     d0, q1                      \n"
    "vqmovun.s16     d1, q2                      \n"

    "vst1.32         d0[0], [%[dst]], %[kBPS]    \n"
    "vst1.32         d0[1], [%[dst]], %[kBPS]    \n"
    "vst1.32         d1[0], [%[dst]], %[kBPS]    \n"
    "vst1.32         d1[1], [%[dst]]             \n"

    : [in] "+r"(in), [dst] "+r"(dst)  /* modified registers */
    : [kBPS] "r"(kBPS), [constants] "r"(constants)  /* constants */
    : "memory", "q0", "q1", "q2", "q8", "q9", "q10", "q11"  /* clobbered */
  );
}

#endif    // WEBP_USE_INTRINSICS

static void TransformTwo_NEON(const int16_t* in, uint8_t* dst, int do_two) {
  TransformOne_NEON(in, dst);
  if (do_two) {
    TransformOne_NEON(in + 16, dst + 4);
  }
}

static void TransformDC_NEON(const int16_t* in, uint8_t* dst) {
  const int16x8_t DC = vdupq_n_s16(in[0]);
  Add4x4_NEON(DC, DC, dst);
}

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

#define STORE_WHT(dst, col, rows) do {                  \
  *dst = vgetq_lane_s32(rows.val[0], col); (dst) += 16; \
  *dst = vgetq_lane_s32(rows.val[1], col); (dst) += 16; \
  *dst = vgetq_lane_s32(rows.val[2], col); (dst) += 16; \
  *dst = vgetq_lane_s32(rows.val[3], col); (dst) += 16; \
} while (0)

static void TransformWHT_NEON(const int16_t* in, int16_t* out) {
  int32x4x4_t tmp;

  {
    // Load the source.
    const int16x4_t in00_03 = vld1_s16(in + 0);
    const int16x4_t in04_07 = vld1_s16(in + 4);
    const int16x4_t in08_11 = vld1_s16(in + 8);
    const int16x4_t in12_15 = vld1_s16(in + 12);
    const int32x4_t a0 = vaddl_s16(in00_03, in12_15);  // in[0..3] + in[12..15]
    const int32x4_t a1 = vaddl_s16(in04_07, in08_11);  // in[4..7] + in[8..11]
    const int32x4_t a2 = vsubl_s16(in04_07, in08_11);  // in[4..7] - in[8..11]
    const int32x4_t a3 = vsubl_s16(in00_03, in12_15);  // in[0..3] - in[12..15]
    tmp.val[0] = vaddq_s32(a0, a1);
    tmp.val[1] = vaddq_s32(a3, a2);
    tmp.val[2] = vsubq_s32(a0, a1);
    tmp.val[3] = vsubq_s32(a3, a2);
    // Arrange the temporary results column-wise.
    tmp = Transpose4x4_NEON(tmp);
  }

  {
    const int32x4_t kCst3 = vdupq_n_s32(3);
    const int32x4_t dc = vaddq_s32(tmp.val[0], kCst3);  // add rounder
    const int32x4_t a0 = vaddq_s32(dc, tmp.val[3]);
    const int32x4_t a1 = vaddq_s32(tmp.val[1], tmp.val[2]);
    const int32x4_t a2 = vsubq_s32(tmp.val[1], tmp.val[2]);
    const int32x4_t a3 = vsubq_s32(dc, tmp.val[3]);

    tmp.val[0] = vaddq_s32(a0, a1);
    tmp.val[1] = vaddq_s32(a3, a2);
    tmp.val[2] = vsubq_s32(a0, a1);
    tmp.val[3] = vsubq_s32(a3, a2);

    // right shift the results by 3.
    tmp.val[0] = vshrq_n_s32(tmp.val[0], 3);
    tmp.val[1] = vshrq_n_s32(tmp.val[1], 3);
    tmp.val[2] = vshrq_n_s32(tmp.val[2], 3);
    tmp.val[3] = vshrq_n_s32(tmp.val[3], 3);

    STORE_WHT(out, 0, tmp);
    STORE_WHT(out, 1, tmp);
    STORE_WHT(out, 2, tmp);
    STORE_WHT(out, 3, tmp);
  }
}

#undef STORE_WHT

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

#define MUL(a, b) (((a) * (b)) >> 16)
static void TransformAC3_NEON(const int16_t* in, uint8_t* dst) {
  static const int kC1_full = 20091 + (1 << 16);
  static const int kC2_full = 35468;
  const int16x4_t A = vld1_dup_s16(in);
  const int16x4_t c4 = vdup_n_s16(MUL(in[4], kC2_full));
  const int16x4_t d4 = vdup_n_s16(MUL(in[4], kC1_full));
  const int c1 = MUL(in[1], kC2_full);
  const int d1 = MUL(in[1], kC1_full);
  const uint64_t cd = (uint64_t)( d1 & 0xffff) <<  0 |
                      (uint64_t)( c1 & 0xffff) << 16 |
                      (uint64_t)(-c1 & 0xffff) << 32 |
                      (uint64_t)(-d1 & 0xffff) << 48;
  const int16x4_t CD = vcreate_s16(cd);
  const int16x4_t B = vqadd_s16(A, CD);
  const int16x8_t m0_m1 = vcombine_s16(vqadd_s16(B, d4), vqadd_s16(B, c4));
  const int16x8_t m2_m3 = vcombine_s16(vqsub_s16(B, c4), vqsub_s16(B, d4));
  Add4x4_NEON(m0_m1, m2_m3, dst);
}
#undef MUL

//------------------------------------------------------------------------------
// 4x4

static void DC4_NEON(uint8_t* dst) {    // DC
  const uint8x8_t A = vld1_u8(dst - BPS);  // top row
  const uint16x4_t p0 = vpaddl_u8(A);  // cascading summation of the top
  const uint16x4_t p1 = vpadd_u16(p0, p0);
  const uint8x8_t L0 = vld1_u8(dst + 0 * BPS - 1);
  const uint8x8_t L1 = vld1_u8(dst + 1 * BPS - 1);
  const uint8x8_t L2 = vld1_u8(dst + 2 * BPS - 1);
  const uint8x8_t L3 = vld1_u8(dst + 3 * BPS - 1);
  const uint16x8_t s0 = vaddl_u8(L0, L1);
  const uint16x8_t s1 = vaddl_u8(L2, L3);
  const uint16x8_t s01 = vaddq_u16(s0, s1);
  const uint16x8_t sum = vaddq_u16(s01, vcombine_u16(p1, p1));
  const uint8x8_t dc0 = vrshrn_n_u16(sum, 3);  // (sum + 4) >> 3
  const uint8x8_t dc = vdup_lane_u8(dc0, 0);
  int i;
  for (i = 0; i < 4; ++i) {
    vst1_lane_u32((uint32_t*)(dst + i * BPS), vreinterpret_u32_u8(dc), 0);
  }
}

// TrueMotion (4x4 + 8x8)
static WEBP_INLINE void TrueMotion_NEON(uint8_t* dst, int size) {
  const uint8x8_t TL = vld1_dup_u8(dst - BPS - 1);  // top-left pixel 'A[-1]'
  const uint8x8_t T = vld1_u8(dst - BPS);  // top row 'A[0..3]'
  const int16x8_t d = vreinterpretq_s16_u16(vsubl_u8(T, TL));  // A[c] - A[-1]
  int y;
  for (y = 0; y < size; y += 4) {
    // left edge
    const int16x8_t L0 = ConvertU8ToS16_NEON(vld1_dup_u8(dst + 0 * BPS - 1));
    const int16x8_t L1 = ConvertU8ToS16_NEON(vld1_dup_u8(dst + 1 * BPS - 1));
    const int16x8_t L2 = ConvertU8ToS16_NEON(vld1_dup_u8(dst + 2 * BPS - 1));
    const int16x8_t L3 = ConvertU8ToS16_NEON(vld1_dup_u8(dst + 3 * BPS - 1));
    const int16x8_t r0 = vaddq_s16(L0, d);  // L[r] + A[c] - A[-1]
    const int16x8_t r1 = vaddq_s16(L1, d);
    const int16x8_t r2 = vaddq_s16(L2, d);
    const int16x8_t r3 = vaddq_s16(L3, d);
    // Saturate and store the result.
    const uint32x2_t r0_u32 = vreinterpret_u32_u8(vqmovun_s16(r0));
    const uint32x2_t r1_u32 = vreinterpret_u32_u8(vqmovun_s16(r1));
    const uint32x2_t r2_u32 = vreinterpret_u32_u8(vqmovun_s16(r2));
    const uint32x2_t r3_u32 = vreinterpret_u32_u8(vqmovun_s16(r3));
    if (size == 4) {
      vst1_lane_u32((uint32_t*)(dst + 0 * BPS), r0_u32, 0);
      vst1_lane_u32((uint32_t*)(dst + 1 * BPS), r1_u32, 0);
      vst1_lane_u32((uint32_t*)(dst + 2 * BPS), r2_u32, 0);
      vst1_lane_u32((uint32_t*)(dst + 3 * BPS), r3_u32, 0);
    } else {
      vst1_u32((uint32_t*)(dst + 0 * BPS), r0_u32);
      vst1_u32((uint32_t*)(dst + 1 * BPS), r1_u32);
      vst1_u32((uint32_t*)(dst + 2 * BPS), r2_u32);
      vst1_u32((uint32_t*)(dst + 3 * BPS), r3_u32);
    }
    dst += 4 * BPS;
  }
}

static void TM4_NEON(uint8_t* dst) { TrueMotion_NEON(dst, 4); }

static void VE4_NEON(uint8_t* dst) {    // vertical
  // NB: avoid vld1_u64 here as an alignment hint may be added -> SIGBUS.
  const uint64x1_t A0 = vreinterpret_u64_u8(vld1_u8(dst - BPS - 1));  // top row
  const uint64x1_t A1 = vshr_n_u64(A0, 8);
  const uint64x1_t A2 = vshr_n_u64(A0, 16);
  const uint8x8_t ABCDEFGH = vreinterpret_u8_u64(A0);
  const uint8x8_t BCDEFGH0 = vreinterpret_u8_u64(A1);
  const uint8x8_t CDEFGH00 = vreinterpret_u8_u64(A2);
  const uint8x8_t b = vhadd_u8(ABCDEFGH, CDEFGH00);
  const uint8x8_t avg = vrhadd_u8(b, BCDEFGH0);
  int i;
  for (i = 0; i < 4; ++i) {
    vst1_lane_u32((uint32_t*)(dst + i * BPS), vreinterpret_u32_u8(avg), 0);
  }
}

static void RD4_NEON(uint8_t* dst) {   // Down-right
  const uint8x8_t XABCD_u8 = vld1_u8(dst - BPS - 1);
  const uint64x1_t XABCD = vreinterpret_u64_u8(XABCD_u8);
  const uint64x1_t ____XABC = vshl_n_u64(XABCD, 32);
  const uint32_t I = dst[-1 + 0 * BPS];
  const uint32_t J = dst[-1 + 1 * BPS];
  const uint32_t K = dst[-1 + 2 * BPS];
  const uint32_t L = dst[-1 + 3 * BPS];
  const uint64x1_t LKJI____ =
      vcreate_u64((uint64_t)L | (K << 8) | (J << 16) | (I << 24));
  const uint64x1_t LKJIXABC = vorr_u64(LKJI____, ____XABC);
  const uint8x8_t KJIXABC_ = vreinterpret_u8_u64(vshr_n_u64(LKJIXABC, 8));
  const uint8x8_t JIXABC__ = vreinterpret_u8_u64(vshr_n_u64(LKJIXABC, 16));
  const uint8_t D = vget_lane_u8(XABCD_u8, 4);
  const uint8x8_t JIXABCD_ = vset_lane_u8(D, JIXABC__, 6);
  const uint8x8_t LKJIXABC_u8 = vreinterpret_u8_u64(LKJIXABC);
  const uint8x8_t avg1 = vhadd_u8(JIXABCD_, LKJIXABC_u8);
  const uint8x8_t avg2 = vrhadd_u8(avg1, KJIXABC_);
  const uint64x1_t avg2_u64 = vreinterpret_u64_u8(avg2);
  const uint32x2_t r3 = vreinterpret_u32_u8(avg2);
  const uint32x2_t r2 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 8));
  const uint32x2_t r1 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 16));
  const uint32x2_t r0 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 24));
  vst1_lane_u32((uint32_t*)(dst + 0 * BPS), r0, 0);
  vst1_lane_u32((uint32_t*)(dst + 1 * BPS), r1, 0);
  vst1_lane_u32((uint32_t*)(dst + 2 * BPS), r2, 0);
  vst1_lane_u32((uint32_t*)(dst + 3 * BPS), r3, 0);
}

static void LD4_NEON(uint8_t* dst) {    // Down-left
  // Note using the same shift trick as VE4() is slower here.
  const uint8x8_t ABCDEFGH = vld1_u8(dst - BPS + 0);
  const uint8x8_t BCDEFGH0 = vld1_u8(dst - BPS + 1);
  const uint8x8_t CDEFGH00 = vld1_u8(dst - BPS + 2);
  const uint8x8_t CDEFGHH0 = vset_lane_u8(dst[-BPS + 7], CDEFGH00, 6);
  const uint8x8_t avg1 = vhadd_u8(ABCDEFGH, CDEFGHH0);
  const uint8x8_t avg2 = vrhadd_u8(avg1, BCDEFGH0);
  const uint64x1_t avg2_u64 = vreinterpret_u64_u8(avg2);
  const uint32x2_t r0 = vreinterpret_u32_u8(avg2);
  const uint32x2_t r1 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 8));
  const uint32x2_t r2 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 16));
  const uint32x2_t r3 = vreinterpret_u32_u64(vshr_n_u64(avg2_u64, 24));
  vst1_lane_u32((uint32_t*)(dst + 0 * BPS), r0, 0);
  vst1_lane_u32((uint32_t*)(dst + 1 * BPS), r1, 0);
  vst1_lane_u32((uint32_t*)(dst + 2 * BPS), r2, 0);
  vst1_lane_u32((uint32_t*)(dst + 3 * BPS), r3, 0);
}

//------------------------------------------------------------------------------
// Chroma

static void VE8uv_NEON(uint8_t* dst) {    // vertical
  const uint8x8_t top = vld1_u8(dst - BPS);
  int j;
  for (j = 0; j < 8; ++j) {
    vst1_u8(dst + j * BPS, top);
  }
}

static void HE8uv_NEON(uint8_t* dst) {    // horizontal
  int j;
  for (j = 0; j < 8; ++j) {
    const uint8x8_t left = vld1_dup_u8(dst - 1);
    vst1_u8(dst, left);
    dst += BPS;
  }
}

static WEBP_INLINE void DC8_NEON(uint8_t* dst, int do_top, int do_left) {
  uint16x8_t sum_top;
  uint16x8_t sum_left;
  uint8x8_t dc0;

  if (do_top) {
    const uint8x8_t A = vld1_u8(dst - BPS);  // top row
#if WEBP_AARCH64
    const uint16_t p2 = vaddlv_u8(A);
    sum_top = vdupq_n_u16(p2);
#else
    const uint16x4_t p0 = vpaddl_u8(A);  // cascading summation of the top
    const uint16x4_t p1 = vpadd_u16(p0, p0);
    const uint16x4_t p2 = vpadd_u16(p1, p1);
    sum_top = vcombine_u16(p2, p2);
#endif
  }

  if (do_left) {
    const uint8x8_t L0 = vld1_u8(dst + 0 * BPS - 1);
    const uint8x8_t L1 = vld1_u8(dst + 1 * BPS - 1);
    const uint8x8_t L2 = vld1_u8(dst + 2 * BPS - 1);
    const uint8x8_t L3 = vld1_u8(dst + 3 * BPS - 1);
    const uint8x8_t L4 = vld1_u8(dst + 4 * BPS - 1);
    const uint8x8_t L5 = vld1_u8(dst + 5 * BPS - 1);
    const uint8x8_t L6 = vld1_u8(dst + 6 * BPS - 1);
    const uint8x8_t L7 = vld1_u8(dst + 7 * BPS - 1);
    const uint16x8_t s0 = vaddl_u8(L0, L1);
    const uint16x8_t s1 = vaddl_u8(L2, L3);
    const uint16x8_t s2 = vaddl_u8(L4, L5);
    const uint16x8_t s3 = vaddl_u8(L6, L7);
    const uint16x8_t s01 = vaddq_u16(s0, s1);
    const uint16x8_t s23 = vaddq_u16(s2, s3);
    sum_left = vaddq_u16(s01, s23);
  }

  if (do_top && do_left) {
    const uint16x8_t sum = vaddq_u16(sum_left, sum_top);
    dc0 = vrshrn_n_u16(sum, 4);
  } else if (do_top) {
    dc0 = vrshrn_n_u16(sum_top, 3);
  } else if (do_left) {
    dc0 = vrshrn_n_u16(sum_left, 3);
  } else {
    dc0 = vdup_n_u8(0x80);
  }

  {
    const uint8x8_t dc = vdup_lane_u8(dc0, 0);
    int i;
    for (i = 0; i < 8; ++i) {
      vst1_u32((uint32_t*)(dst + i * BPS), vreinterpret_u32_u8(dc));
    }
  }
}

static void DC8uv_NEON(uint8_t* dst) { DC8_NEON(dst, 1, 1); }
static void DC8uvNoTop_NEON(uint8_t* dst) { DC8_NEON(dst, 0, 1); }
static void DC8uvNoLeft_NEON(uint8_t* dst) { DC8_NEON(dst, 1, 0); }
static void DC8uvNoTopLeft_NEON(uint8_t* dst) { DC8_NEON(dst, 0, 0); }

static void TM8uv_NEON(uint8_t* dst) { TrueMotion_NEON(dst, 8); }

//------------------------------------------------------------------------------
// 16x16

static void VE16_NEON(uint8_t* dst) {     // vertical
  const uint8x16_t top = vld1q_u8(dst - BPS);
  int j;
  for (j = 0; j < 16; ++j) {
    vst1q_u8(dst + j * BPS, top);
  }
}

static void HE16_NEON(uint8_t* dst) {     // horizontal
  int j;
  for (j = 0; j < 16; ++j) {
    const uint8x16_t left = vld1q_dup_u8(dst - 1);
    vst1q_u8(dst, left);
    dst += BPS;
  }
}

static WEBP_INLINE void DC16_NEON(uint8_t* dst, int do_top, int do_left) {
  uint16x8_t sum_top;
  uint16x8_t sum_left;
  uint8x8_t dc0;

  if (do_top) {
    const uint8x16_t A = vld1q_u8(dst - BPS);  // top row
#if WEBP_AARCH64
    const uint16_t p3 = vaddlvq_u8(A);
    sum_top = vdupq_n_u16(p3);
#else
    const uint16x8_t p0 = vpaddlq_u8(A);  // cascading summation of the top
    const uint16x4_t p1 = vadd_u16(vget_low_u16(p0), vget_high_u16(p0));
    const uint16x4_t p2 = vpadd_u16(p1, p1);
    const uint16x4_t p3 = vpadd_u16(p2, p2);
    sum_top = vcombine_u16(p3, p3);
#endif
  }

  if (do_left) {
    int i;
    sum_left = vdupq_n_u16(0);
    for (i = 0; i < 16; i += 8) {
      const uint8x8_t L0 = vld1_u8(dst + (i + 0) * BPS - 1);
      const uint8x8_t L1 = vld1_u8(dst + (i + 1) * BPS - 1);
      const uint8x8_t L2 = vld1_u8(dst + (i + 2) * BPS - 1);
      const uint8x8_t L3 = vld1_u8(dst + (i + 3) * BPS - 1);
      const uint8x8_t L4 = vld1_u8(dst + (i + 4) * BPS - 1);
      const uint8x8_t L5 = vld1_u8(dst + (i + 5) * BPS - 1);
      const uint8x8_t L6 = vld1_u8(dst + (i + 6) * BPS - 1);
      const uint8x8_t L7 = vld1_u8(dst + (i + 7) * BPS - 1);
      const uint16x8_t s0 = vaddl_u8(L0, L1);
      const uint16x8_t s1 = vaddl_u8(L2, L3);
      const uint16x8_t s2 = vaddl_u8(L4, L5);
      const uint16x8_t s3 = vaddl_u8(L6, L7);
      const uint16x8_t s01 = vaddq_u16(s0, s1);
      const uint16x8_t s23 = vaddq_u16(s2, s3);
      const uint16x8_t sum = vaddq_u16(s01, s23);
      sum_left = vaddq_u16(sum_left, sum);
    }
  }

  if (do_top && do_left) {
    const uint16x8_t sum = vaddq_u16(sum_left, sum_top);
    dc0 = vrshrn_n_u16(sum, 5);
  } else if (do_top) {
    dc0 = vrshrn_n_u16(sum_top, 4);
  } else if (do_left) {
    dc0 = vrshrn_n_u16(sum_left, 4);
  } else {
    dc0 = vdup_n_u8(0x80);
  }

  {
    const uint8x16_t dc = vdupq_lane_u8(dc0, 0);
    int i;
    for (i = 0; i < 16; ++i) {
      vst1q_u8(dst + i * BPS, dc);
    }
  }
}

static void DC16TopLeft_NEON(uint8_t* dst) { DC16_NEON(dst, 1, 1); }
static void DC16NoTop_NEON(uint8_t* dst) { DC16_NEON(dst, 0, 1); }
static void DC16NoLeft_NEON(uint8_t* dst) { DC16_NEON(dst, 1, 0); }
static void DC16NoTopLeft_NEON(uint8_t* dst) { DC16_NEON(dst, 0, 0); }

static void TM16_NEON(uint8_t* dst) {
  const uint8x8_t TL = vld1_dup_u8(dst - BPS - 1);  // top-left pixel 'A[-1]'
  const uint8x16_t T = vld1q_u8(dst - BPS);  // top row 'A[0..15]'
  // A[c] - A[-1]
  const int16x8_t d_lo = vreinterpretq_s16_u16(vsubl_u8(vget_low_u8(T), TL));
  const int16x8_t d_hi = vreinterpretq_s16_u16(vsubl_u8(vget_high_u8(T), TL));
  int y;
  for (y = 0; y < 16; y += 4) {
    // left edge
    const int16x8_t L0 = ConvertU8ToS16_NEON(vld1_dup_u8(dst + 0 * BPS - 1));
    const int16x8_t L1 = ConvertU8ToS16_NEON(vld1_dup_u8(dst + 1 * BPS - 1));
    const int16x8_t L2 = ConvertU8ToS16_NEON(vld1_dup_u8(dst + 2 * BPS - 1));
    const int16x8_t L3 = ConvertU8ToS16_NEON(vld1_dup_u8(dst + 3 * BPS - 1));
    const int16x8_t r0_lo = vaddq_s16(L0, d_lo);  // L[r] + A[c] - A[-1]
    const int16x8_t r1_lo = vaddq_s16(L1, d_lo);
    const int16x8_t r2_lo = vaddq_s16(L2, d_lo);
    const int16x8_t r3_lo = vaddq_s16(L3, d_lo);
    const int16x8_t r0_hi = vaddq_s16(L0, d_hi);
    const int16x8_t r1_hi = vaddq_s16(L1, d_hi);
    const int16x8_t r2_hi = vaddq_s16(L2, d_hi);
    const int16x8_t r3_hi = vaddq_s16(L3, d_hi);
    // Saturate and store the result.
    const uint8x16_t row0 = vcombine_u8(vqmovun_s16(r0_lo), vqmovun_s16(r0_hi));
    const uint8x16_t row1 = vcombine_u8(vqmovun_s16(r1_lo), vqmovun_s16(r1_hi));
    const uint8x16_t row2 = vcombine_u8(vqmovun_s16(r2_lo), vqmovun_s16(r2_hi));
    const uint8x16_t row3 = vcombine_u8(vqmovun_s16(r3_lo), vqmovun_s16(r3_hi));
    vst1q_u8(dst + 0 * BPS, row0);
    vst1q_u8(dst + 1 * BPS, row1);
    vst1q_u8(dst + 2 * BPS, row2);
    vst1q_u8(dst + 3 * BPS, row3);
    dst += 4 * BPS;
  }
}

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

extern void VP8DspInitNEON(void);

WEBP_TSAN_IGNORE_FUNCTION void VP8DspInitNEON(void) {
  VP8Transform = TransformTwo_NEON;
  VP8TransformAC3 = TransformAC3_NEON;
  VP8TransformDC = TransformDC_NEON;
  VP8TransformWHT = TransformWHT_NEON;

  VP8VFilter16 = VFilter16_NEON;
  VP8VFilter16i = VFilter16i_NEON;
  VP8HFilter16 = HFilter16_NEON;
#if !defined(WORK_AROUND_GCC)
  VP8HFilter16i = HFilter16i_NEON;
#endif
  VP8VFilter8 = VFilter8_NEON;
  VP8VFilter8i = VFilter8i_NEON;
#if !defined(WORK_AROUND_GCC)
  VP8HFilter8 = HFilter8_NEON;
  VP8HFilter8i = HFilter8i_NEON;
#endif
  VP8SimpleVFilter16 = SimpleVFilter16_NEON;
  VP8SimpleHFilter16 = SimpleHFilter16_NEON;
  VP8SimpleVFilter16i = SimpleVFilter16i_NEON;
  VP8SimpleHFilter16i = SimpleHFilter16i_NEON;

  VP8PredLuma4[0] = DC4_NEON;
  VP8PredLuma4[1] = TM4_NEON;
  VP8PredLuma4[2] = VE4_NEON;
  VP8PredLuma4[4] = RD4_NEON;
  VP8PredLuma4[6] = LD4_NEON;

  VP8PredLuma16[0] = DC16TopLeft_NEON;
  VP8PredLuma16[1] = TM16_NEON;
  VP8PredLuma16[2] = VE16_NEON;
  VP8PredLuma16[3] = HE16_NEON;
  VP8PredLuma16[4] = DC16NoTop_NEON;
  VP8PredLuma16[5] = DC16NoLeft_NEON;
  VP8PredLuma16[6] = DC16NoTopLeft_NEON;

  VP8PredChroma8[0] = DC8uv_NEON;
  VP8PredChroma8[1] = TM8uv_NEON;
  VP8PredChroma8[2] = VE8uv_NEON;
  VP8PredChroma8[3] = HE8uv_NEON;
  VP8PredChroma8[4] = DC8uvNoTop_NEON;
  VP8PredChroma8[5] = DC8uvNoLeft_NEON;
  VP8PredChroma8[6] = DC8uvNoTopLeft_NEON;
}

#else  // !WEBP_USE_NEON

WEBP_DSP_INIT_STUB(VP8DspInitNEON)

#endif  // WEBP_USE_NEON