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
|
/*
* ARM NEON optimised FFT
*
* Copyright (c) 2009 Mans Rullgard <mans@mansr.com>
* Copyright (c) 2009 Naotoshi Nojiri
* Copyright (c) 2014 Janne Grunau <janne-libav@jannau.net>
*
* This algorithm (though not any of the implementation details) is
* based on libdjbfft by D. J. Bernstein.
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/aarch64/asm.S"
#define M_SQRT1_2 0.70710678118654752440
.macro transpose d0, d1, s0, s1
trn1 \d0, \s0, \s1
trn2 \d1, \s0, \s1
.endm
function fft4_neon
ld1 {v0.2s,v1.2s,v2.2s,v3.2s}, [x0]
fadd v4.2s, v0.2s, v1.2s // r0+r1,i0+i1
fsub v6.2s, v0.2s, v1.2s // r0-r1,i0-i1
ext v16.8b, v2.8b, v3.8b, #4
ext v17.8b, v3.8b, v2.8b, #4
fadd v5.2s, v2.2s, v3.2s // i2+i3,r2+r3
fsub v7.2s, v16.2s, v17.2s // r3-r2,i2-i3
fadd v0.2s, v4.2s, v5.2s
fsub v2.2s, v4.2s, v5.2s
fadd v1.2s, v6.2s, v7.2s
fsub v3.2s, v6.2s, v7.2s
st1 {v0.2s,v1.2s,v2.2s,v3.2s}, [x0]
ret
endfunc
function fft8_neon
mov x1, x0
ld1 {v0.2s, v1.2s, v2.2s, v3.2s}, [x0], #32
ld1 {v16.2s,v17.2s,v18.2s,v19.2s}, [x0]
ext v22.8b, v2.8b, v3.8b, #4
ext v23.8b, v3.8b, v2.8b, #4
fadd v4.2s, v16.2s, v17.2s // r4+r5,i4+i5
fadd v5.2s, v18.2s, v19.2s // r6+r7,i6+i7
fsub v17.2s, v16.2s, v17.2s // r4-r5,i4-i5
fsub v19.2s, v18.2s, v19.2s // r6-r7,i6-i7
rev64 v27.2s, v28.2s // ???
fadd v20.2s, v0.2s, v1.2s // r0+r1,i0+i1
fadd v21.2s, v2.2s, v3.2s // r2+r3,i2+i3
fmul v26.2s, v17.2s, v28.2s // -a2r*w,a2i*w
ext v6.8b, v4.8b, v5.8b, #4
ext v7.8b, v5.8b, v4.8b, #4
fmul v27.2s, v19.2s, v27.2s // a3r*w,-a3i*w
fsub v23.2s, v22.2s, v23.2s // i2-i3,r3-r2
fsub v22.2s, v0.2s, v1.2s // r0-r1,i0-i1
fmul v24.2s, v17.2s, v28.s[1] // a2r*w,a2i*w
fmul v25.2s, v19.2s, v28.s[1] // a3r*w,a3i*w
fadd v0.2s, v20.2s, v21.2s
fsub v2.2s, v20.2s, v21.2s
fadd v1.2s, v22.2s, v23.2s
rev64 v26.2s, v26.2s
rev64 v27.2s, v27.2s
fsub v3.2s, v22.2s, v23.2s
fsub v6.2s, v6.2s, v7.2s
fadd v24.2s, v24.2s, v26.2s // a2r+a2i,a2i-a2r t1,t2
fadd v25.2s, v25.2s, v27.2s // a3r-a3i,a3i+a3r t5,t6
fadd v7.2s, v4.2s, v5.2s
fsub v18.2s, v2.2s, v6.2s
ext v26.8b, v24.8b, v25.8b, #4
ext v27.8b, v25.8b, v24.8b, #4
fadd v2.2s, v2.2s, v6.2s
fsub v16.2s, v0.2s, v7.2s
fadd v5.2s, v25.2s, v24.2s
fsub v4.2s, v26.2s, v27.2s
fadd v0.2s, v0.2s, v7.2s
fsub v17.2s, v1.2s, v5.2s
fsub v19.2s, v3.2s, v4.2s
fadd v3.2s, v3.2s, v4.2s
fadd v1.2s, v1.2s, v5.2s
st1 {v16.2s,v17.2s,v18.2s,v19.2s}, [x0]
st1 {v0.2s, v1.2s, v2.2s, v3.2s}, [x1]
ret
endfunc
function fft16_neon
mov x1, x0
ld1 {v0.2s, v1.2s, v2.2s, v3.2s}, [x0], #32
ld1 {v16.2s,v17.2s,v18.2s,v19.2s}, [x0], #32
ext v22.8b, v2.8b, v3.8b, #4
ext v23.8b, v3.8b, v2.8b, #4
fadd v4.2s, v16.2s, v17.2s // r4+r5,i4+i5
fadd v5.2s, v18.2s, v19.2s // r6+r7,i6+i7
fsub v17.2s, v16.2s, v17.2s // r4-r5,i4-i5
fsub v19.2s, v18.2s, v19.2s // r6-r7,i6-i7
rev64 v27.2s, v28.2s // ???
fadd v20.2s, v0.2s, v1.2s // r0+r1,i0+i1
fadd v21.2s, v2.2s, v3.2s // r2+r3,i2+i3
fmul v26.2s, v17.2s, v28.2s // -a2r*w,a2i*w
ext v6.8b, v4.8b, v5.8b, #4
ext v7.8b, v5.8b, v4.8b, #4
fmul v27.2s, v19.2s, v27.2s // a3r*w,-a3i*w
fsub v23.2s, v22.2s, v23.2s // i2-i3,r3-r2
fsub v22.2s, v0.2s, v1.2s // r0-r1,i0-i1
fmul v24.2s, v17.2s, v28.s[1] // a2r*w,a2i*w
fmul v25.2s, v19.2s, v28.s[1] // a3r*w,a3i*w
fadd v0.2s, v20.2s, v21.2s
fsub v2.2s, v20.2s, v21.2s
fadd v1.2s, v22.2s, v23.2s
rev64 v26.2s, v26.2s
rev64 v27.2s, v27.2s
fsub v3.2s, v22.2s, v23.2s
fsub v6.2s, v6.2s, v7.2s
fadd v24.2s, v24.2s, v26.2s // a2r+a2i,a2i-a2r t1,t2
fadd v25.2s, v25.2s, v27.2s // a3r-a3i,a3i+a3r t5,t6
fadd v7.2s, v4.2s, v5.2s
fsub v18.2s, v2.2s, v6.2s
ld1 {v20.4s,v21.4s}, [x0], #32
ld1 {v22.4s,v23.4s}, [x0], #32
ext v26.8b, v24.8b, v25.8b, #4
ext v27.8b, v25.8b, v24.8b, #4
fadd v2.2s, v2.2s, v6.2s
fsub v16.2s, v0.2s, v7.2s
fadd v5.2s, v25.2s, v24.2s
fsub v4.2s, v26.2s, v27.2s
transpose v24.2d, v25.2d, v20.2d, v22.2d
transpose v26.2d, v27.2d, v21.2d, v23.2d
fadd v0.2s, v0.2s, v7.2s
fsub v17.2s, v1.2s, v5.2s
fsub v19.2s, v3.2s, v4.2s
fadd v3.2s, v3.2s, v4.2s
fadd v1.2s, v1.2s, v5.2s
ext v20.16b, v21.16b, v21.16b, #4
ext v21.16b, v23.16b, v23.16b, #4
zip1 v0.2d, v0.2d, v1.2d // {z[0], z[1]}
zip1 v1.2d, v2.2d, v3.2d // {z[2], z[3]}
zip1 v2.2d, v16.2d, v17.2d // {z[o1], z[o1+1]}
zip1 v3.2d, v18.2d, v19.2d // {z[o1+2],z[o1+3]}
// 2 x fft4
transpose v22.2d, v23.2d, v20.2d, v21.2d
fadd v4.4s, v24.4s, v25.4s
fadd v5.4s, v26.4s, v27.4s
fsub v6.4s, v24.4s, v25.4s
fsub v7.4s, v22.4s, v23.4s
ld1 {v23.4s}, [x14]
fadd v24.4s, v4.4s, v5.4s // {z[o2+0],z[o2+1]}
fsub v26.4s, v4.4s, v5.4s // {z[o2+2],z[o2+3]}
fadd v25.4s, v6.4s, v7.4s // {z[o3+0],z[o3+1]}
fsub v27.4s, v6.4s, v7.4s // {z[o3+2],z[o3+3]}
//fft_pass_neon_16
rev64 v7.4s, v25.4s
fmul v25.4s, v25.4s, v23.s[1]
fmul v7.4s, v7.4s, v29.4s
fmla v25.4s, v7.4s, v23.s[3] // {t1a,t2a,t5a,t6a}
zip1 v20.4s, v24.4s, v25.4s
zip2 v21.4s, v24.4s, v25.4s
fneg v22.4s, v20.4s
fadd v4.4s, v21.4s, v20.4s
fsub v6.4s, v20.4s, v21.4s // just the second half
fadd v5.4s, v21.4s, v22.4s // just the first half
tbl v4.16b, {v4.16b}, v30.16b // trans4_float
tbl v5.16b, {v5.16b,v6.16b}, v31.16b // trans8_float
fsub v20.4s, v0.4s, v4.4s // {z[o2],z[o2+1]}
fadd v16.4s, v0.4s, v4.4s // {z[0], z[1]}
fsub v22.4s, v2.4s, v5.4s // {z[o3],z[o3+1]}
fadd v18.4s, v2.4s, v5.4s // {z[o1],z[o1+1]}
//second half
rev64 v6.4s, v26.4s
fmul v26.4s, v26.4s, v23.s[2]
rev64 v7.4s, v27.4s
fmul v27.4s, v27.4s, v23.s[3]
fmul v6.4s, v6.4s, v29.4s
fmul v7.4s, v7.4s, v29.4s
fmla v26.4s, v6.4s, v23.s[2] // {t1,t2,t5,t6}
fmla v27.4s, v7.4s, v23.s[1] // {t1a,t2a,t5a,t6a}
zip1 v24.4s, v26.4s, v27.4s
zip2 v25.4s, v26.4s, v27.4s
fneg v26.4s, v24.4s
fadd v4.4s, v25.4s, v24.4s
fsub v6.4s, v24.4s, v25.4s // just the second half
fadd v5.4s, v25.4s, v26.4s // just the first half
tbl v4.16b, {v4.16b}, v30.16b // trans4_float
tbl v5.16b, {v5.16b,v6.16b}, v31.16b // trans8_float
fadd v17.4s, v1.4s, v4.4s // {z[2], z[3]}
fsub v21.4s, v1.4s, v4.4s // {z[o2+2],z[o2+3]}
fadd v19.4s, v3.4s, v5.4s // {z[o1+2],z[o1+3]}
fsub v23.4s, v3.4s, v5.4s // {z[o3+2],z[o3+3]}
st1 {v16.4s,v17.4s}, [x1], #32
st1 {v18.4s,v19.4s}, [x1], #32
st1 {v20.4s,v21.4s}, [x1], #32
st1 {v22.4s,v23.4s}, [x1], #32
ret
endfunc
const trans4_float, align=4
.byte 0, 1, 2, 3
.byte 8, 9, 10, 11
.byte 4, 5, 6, 7
.byte 12, 13, 14, 15
endconst
const trans8_float, align=4
.byte 24, 25, 26, 27
.byte 0, 1, 2, 3
.byte 28, 29, 30, 31
.byte 4, 5, 6, 7
endconst
function fft_pass_neon
sub x6, x2, #1 // n - 1, loop counter
lsl x5, x2, #3 // 2 * n * sizeof FFTSample
lsl x1, x2, #4 // 2 * n * sizeof FFTComplex
add x5, x4, x5 // wim
add x3, x1, x2, lsl #5 // 4 * n * sizeof FFTComplex
add x2, x0, x2, lsl #5 // &z[o2]
add x3, x0, x3 // &z[o3]
add x1, x0, x1 // &z[o1]
ld1 {v20.4s},[x2] // {z[o2],z[o2+1]}
ld1 {v22.4s},[x3] // {z[o3],z[o3+1]}
ld1 {v4.2s}, [x4], #8 // {wre[0],wre[1]}
trn2 v25.2d, v20.2d, v22.2d
sub x5, x5, #4 // wim--
trn1 v24.2d, v20.2d, v22.2d
ld1 {v5.s}[0], [x5], x7 // d5[0] = wim[-1]
rev64 v7.4s, v25.4s
fmul v25.4s, v25.4s, v4.s[1]
ld1 {v16.4s}, [x0] // {z[0],z[1]}
fmul v7.4s, v7.4s, v29.4s
ld1 {v17.4s}, [x1] // {z[o1],z[o1+1]}
prfm pldl1keep, [x2, #16]
prfm pldl1keep, [x3, #16]
fmla v25.4s, v7.4s, v5.s[0] // {t1a,t2a,t5a,t6a}
prfm pldl1keep, [x0, #16]
prfm pldl1keep, [x1, #16]
zip1 v20.4s, v24.4s, v25.4s
zip2 v21.4s, v24.4s, v25.4s
fneg v22.4s, v20.4s
fadd v4.4s, v21.4s, v20.4s
fsub v6.4s, v20.4s, v21.4s // just the second half
fadd v5.4s, v21.4s, v22.4s // just the first half
tbl v4.16b, {v4.16b}, v30.16b // trans4_float
tbl v5.16b, {v5.16b,v6.16b}, v31.16b // trans8_float
fadd v20.4s, v16.4s, v4.4s
fsub v22.4s, v16.4s, v4.4s
fadd v21.4s, v17.4s, v5.4s
st1 {v20.4s}, [x0], #16 // {z[0], z[1]}
fsub v23.4s, v17.4s, v5.4s
st1 {v21.4s}, [x1], #16 // {z[o1],z[o1+1]}
st1 {v22.4s}, [x2], #16 // {z[o2],z[o2+1]}
st1 {v23.4s}, [x3], #16 // {z[o3],z[o3+1]}
1:
ld1 {v20.4s},[x2] // {z[o2],z[o2+1]}
ld1 {v22.4s},[x3] // {z[o3],z[o3+1]}
ld1 {v4.2s}, [x4], #8 // {wre[0],wre[1]}
transpose v26.2d, v27.2d, v20.2d, v22.2d
ld1 {v5.2s}, [x5], x7 // {wim[-1],wim[0]}
rev64 v6.4s, v26.4s
fmul v26.4s, v26.4s, v4.s[0]
rev64 v7.4s, v27.4s
fmul v27.4s, v27.4s, v4.s[1]
fmul v6.4s, v6.4s, v29.4s
fmul v7.4s, v7.4s, v29.4s
ld1 {v16.4s},[x0] // {z[0],z[1]}
fmla v26.4s, v6.4s, v5.s[1] // {t1,t2,t5,t6}
fmla v27.4s, v7.4s, v5.s[0] // {t1a,t2a,t5a,t6a}
ld1 {v17.4s},[x1] // {z[o1],z[o1+1]}
subs x6, x6, #1 // n--
zip1 v20.4s, v26.4s, v27.4s
zip2 v21.4s, v26.4s, v27.4s
fneg v22.4s, v20.4s
fadd v4.4s, v21.4s, v20.4s
fsub v6.4s, v20.4s, v21.4s // just the second half
fadd v5.4s, v21.4s, v22.4s // just the first half
tbl v4.16b, {v4.16b}, v30.16b // trans4_float
tbl v5.16b, {v5.16b,v6.16b}, v31.16b // trans8_float
fadd v20.4s, v16.4s, v4.4s
fsub v22.4s, v16.4s, v4.4s
fadd v21.4s, v17.4s, v5.4s
st1 {v20.4s}, [x0], #16 // {z[0], z[1]}
fsub v23.4s, v17.4s, v5.4s
st1 {v21.4s}, [x1], #16 // {z[o1],z[o1+1]}
st1 {v22.4s}, [x2], #16 // {z[o2],z[o2+1]}
st1 {v23.4s}, [x3], #16 // {z[o3],z[o3+1]}
b.ne 1b
ret
endfunc
.macro def_fft n, n2, n4
function fft\n\()_neon, align=6
sub sp, sp, #16
stp x28, x30, [sp]
add x28, x0, #\n4*2*8
bl fft\n2\()_neon
mov x0, x28
bl fft\n4\()_neon
add x0, x28, #\n4*1*8
bl fft\n4\()_neon
sub x0, x28, #\n4*2*8
ldp x28, x30, [sp], #16
movrel x4, X(ff_cos_\n)
mov x2, #\n4>>1
b fft_pass_neon
endfunc
.endm
def_fft 32, 16, 8
def_fft 64, 32, 16
def_fft 128, 64, 32
def_fft 256, 128, 64
def_fft 512, 256, 128
def_fft 1024, 512, 256
def_fft 2048, 1024, 512
def_fft 4096, 2048, 1024
def_fft 8192, 4096, 2048
def_fft 16384, 8192, 4096
def_fft 32768, 16384, 8192
def_fft 65536, 32768, 16384
function ff_fft_calc_neon, export=1
prfm pldl1keep, [x1]
movrel x10, trans4_float
ldr w2, [x0]
movrel x11, trans8_float
sub w2, w2, #2
movrel x3, fft_tab_neon
ld1 {v30.16b}, [x10]
mov x7, #-8
movrel x12, pmmp
ldr x3, [x3, x2, lsl #3]
movrel x13, mppm
movrel x14, X(ff_cos_16)
ld1 {v31.16b}, [x11]
mov x0, x1
ld1 {v29.4s}, [x12] // pmmp
ld1 {v28.4s}, [x13]
br x3
endfunc
function ff_fft_permute_neon, export=1
mov x6, #1
ldr w2, [x0] // nbits
ldr x3, [x0, #16] // tmp_buf
ldr x0, [x0, #8] // revtab
lsl x6, x6, x2
mov x2, x6
1:
ld1 {v0.2s,v1.2s}, [x1], #16
ldr w4, [x0], #4
uxth w5, w4
lsr w4, w4, #16
add x5, x3, x5, lsl #3
add x4, x3, x4, lsl #3
st1 {v0.2s}, [x5]
st1 {v1.2s}, [x4]
subs x6, x6, #2
b.gt 1b
sub x1, x1, x2, lsl #3
1:
ld1 {v0.4s,v1.4s}, [x3], #32
st1 {v0.4s,v1.4s}, [x1], #32
subs x2, x2, #4
b.gt 1b
ret
endfunc
const fft_tab_neon, relocate=1
.quad fft4_neon
.quad fft8_neon
.quad fft16_neon
.quad fft32_neon
.quad fft64_neon
.quad fft128_neon
.quad fft256_neon
.quad fft512_neon
.quad fft1024_neon
.quad fft2048_neon
.quad fft4096_neon
.quad fft8192_neon
.quad fft16384_neon
.quad fft32768_neon
.quad fft65536_neon
endconst
const pmmp, align=4
.float +1.0, -1.0, -1.0, +1.0
endconst
const mppm, align=4
.float -M_SQRT1_2, M_SQRT1_2, M_SQRT1_2, -M_SQRT1_2
endconst
|