GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/fft_template.c Lines: 257 277 92.8 %
Date: 2021-04-18 21:26:34 Branches: 60 78 76.9 %

Line Branch Exec Source
1
/*
2
 * FFT/IFFT transforms
3
 * Copyright (c) 2008 Loren Merritt
4
 * Copyright (c) 2002 Fabrice Bellard
5
 * Partly based on libdjbfft by D. J. Bernstein
6
 *
7
 * This file is part of FFmpeg.
8
 *
9
 * FFmpeg is free software; you can redistribute it and/or
10
 * modify it under the terms of the GNU Lesser General Public
11
 * License as published by the Free Software Foundation; either
12
 * version 2.1 of the License, or (at your option) any later version.
13
 *
14
 * FFmpeg is distributed in the hope that it will be useful,
15
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17
 * Lesser General Public License for more details.
18
 *
19
 * You should have received a copy of the GNU Lesser General Public
20
 * License along with FFmpeg; if not, write to the Free Software
21
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22
 */
23
24
/**
25
 * @file
26
 * FFT/IFFT transforms.
27
 */
28
29
#include <stdlib.h>
30
#include <string.h>
31
#include "libavutil/mathematics.h"
32
#include "libavutil/thread.h"
33
#include "fft.h"
34
#include "fft-internal.h"
35
36
#if FFT_FIXED_32
37
#include "fft_table.h"
38
#else /* FFT_FIXED_32 */
39
40
/* cos(2*pi*x/n) for 0<=x<=n/4, followed by its reverse */
41
#if !CONFIG_HARDCODED_TABLES
42
COSTABLE(16);
43
COSTABLE(32);
44
COSTABLE(64);
45
COSTABLE(128);
46
COSTABLE(256);
47
COSTABLE(512);
48
COSTABLE(1024);
49
COSTABLE(2048);
50
COSTABLE(4096);
51
COSTABLE(8192);
52
COSTABLE(16384);
53
COSTABLE(32768);
54
COSTABLE(65536);
55
COSTABLE(131072);
56
57
2462
static av_cold void init_ff_cos_tabs(int index)
58
{
59
    int i;
60
2462
    int m = 1<<index;
61
2462
    double freq = 2*M_PI/m;
62
2462
    FFTSample *tab = FFT_NAME(ff_cos_tabs)[index];
63
181712
    for(i=0; i<=m/4; i++)
64
179250
        tab[i] = FIX15(cos(i*freq));
65
176788
    for(i=1; i<m/4; i++)
66
174326
        tab[m/2-i] = tab[i];
67
2462
}
68
69
typedef struct CosTabsInitOnce {
70
    void (*func)(void);
71
    AVOnce control;
72
} CosTabsInitOnce;
73
74
#define INIT_FF_COS_TABS_FUNC(index, size)          \
75
static av_cold void init_ff_cos_tabs_ ## size (void)\
76
{                                                   \
77
    init_ff_cos_tabs(index);                        \
78
}
79
80
485
INIT_FF_COS_TABS_FUNC(4, 16)
81
468
INIT_FF_COS_TABS_FUNC(5, 32)
82
394
INIT_FF_COS_TABS_FUNC(6, 64)
83
370
INIT_FF_COS_TABS_FUNC(7, 128)
84
314
INIT_FF_COS_TABS_FUNC(8, 256)
85
290
INIT_FF_COS_TABS_FUNC(9, 512)
86
68
INIT_FF_COS_TABS_FUNC(10, 1024)
87
37
INIT_FF_COS_TABS_FUNC(11, 2048)
88
24
INIT_FF_COS_TABS_FUNC(12, 4096)
89
7
INIT_FF_COS_TABS_FUNC(13, 8192)
90
5
INIT_FF_COS_TABS_FUNC(14, 16384)
91
INIT_FF_COS_TABS_FUNC(15, 32768)
92
INIT_FF_COS_TABS_FUNC(16, 65536)
93
INIT_FF_COS_TABS_FUNC(17, 131072)
94
95
static CosTabsInitOnce cos_tabs_init_once[] = {
96
    { NULL },
97
    { NULL },
98
    { NULL },
99
    { NULL },
100
    { init_ff_cos_tabs_16, AV_ONCE_INIT },
101
    { init_ff_cos_tabs_32, AV_ONCE_INIT },
102
    { init_ff_cos_tabs_64, AV_ONCE_INIT },
103
    { init_ff_cos_tabs_128, AV_ONCE_INIT },
104
    { init_ff_cos_tabs_256, AV_ONCE_INIT },
105
    { init_ff_cos_tabs_512, AV_ONCE_INIT },
106
    { init_ff_cos_tabs_1024, AV_ONCE_INIT },
107
    { init_ff_cos_tabs_2048, AV_ONCE_INIT },
108
    { init_ff_cos_tabs_4096, AV_ONCE_INIT },
109
    { init_ff_cos_tabs_8192, AV_ONCE_INIT },
110
    { init_ff_cos_tabs_16384, AV_ONCE_INIT },
111
    { init_ff_cos_tabs_32768, AV_ONCE_INIT },
112
    { init_ff_cos_tabs_65536, AV_ONCE_INIT },
113
    { init_ff_cos_tabs_131072, AV_ONCE_INIT },
114
};
115
116
10594
av_cold void ff_init_ff_cos_tabs(int index)
117
{
118
10594
    ff_thread_once(&cos_tabs_init_once[index].control, cos_tabs_init_once[index].func);
119
10594
}
120
#endif
121
COSTABLE_CONST FFTSample * const FFT_NAME(ff_cos_tabs)[] = {
122
    NULL, NULL, NULL, NULL,
123
    FFT_NAME(ff_cos_16),
124
    FFT_NAME(ff_cos_32),
125
    FFT_NAME(ff_cos_64),
126
    FFT_NAME(ff_cos_128),
127
    FFT_NAME(ff_cos_256),
128
    FFT_NAME(ff_cos_512),
129
    FFT_NAME(ff_cos_1024),
130
    FFT_NAME(ff_cos_2048),
131
    FFT_NAME(ff_cos_4096),
132
    FFT_NAME(ff_cos_8192),
133
    FFT_NAME(ff_cos_16384),
134
    FFT_NAME(ff_cos_32768),
135
    FFT_NAME(ff_cos_65536),
136
    FFT_NAME(ff_cos_131072),
137
};
138
139
#endif /* FFT_FIXED_32 */
140
141
static void fft_permute_c(FFTContext *s, FFTComplex *z);
142
static void fft_calc_c(FFTContext *s, FFTComplex *z);
143
144
5177636
static int split_radix_permutation(int i, int n, int inverse)
145
{
146
    int m;
147
5177636
    if(n <= 2) return i&1;
148
4412228
    m = n >> 1;
149
4412228
    if(!(i&m))            return split_radix_permutation(i, m, inverse)*2;
150
2206114
    m >>= 1;
151
2206114
    if(inverse == !(i&m)) return split_radix_permutation(i, m, inverse)*4 + 1;
152
1103057
    else                  return split_radix_permutation(i, m, inverse)*4 - 1;
153
}
154
155
156
static const int avx_tab[] = {
157
    0, 4, 1, 5, 8, 12, 9, 13, 2, 6, 3, 7, 10, 14, 11, 15
158
};
159
160
15270
static int is_second_half_of_fft32(int i, int n)
161
{
162
15270
    if (n <= 32)
163
4318
        return i >= 16;
164
10952
    else if (i < n/2)
165
5476
        return is_second_half_of_fft32(i, n/2);
166
5476
    else if (i < 3*n/4)
167
2738
        return is_second_half_of_fft32(i - n/2, n/4);
168
    else
169
2738
        return is_second_half_of_fft32(i - 3*n/4, n/4);
170
}
171
172
325
static av_cold void fft_perm_avx(FFTContext *s)
173
{
174
    int i;
175
325
    int n = 1 << s->nbits;
176
177
4643
    for (i = 0; i < n; i += 16) {
178
        int k;
179
4318
        if (is_second_half_of_fft32(i, n)) {
180
25109
            for (k = 0; k < 16; k++)
181
47264
                s->revtab[-split_radix_permutation(i + k, n, s->inverse) & (n - 1)] =
182
23632
                    i + avx_tab[k];
183
184
        } else {
185
48297
            for (k = 0; k < 16; k++) {
186
45456
                int j = i + k;
187
45456
                j = (j & ~7) | ((j >> 1) & 3) | ((j << 2) & 4);
188
45456
                s->revtab[-split_radix_permutation(i + k, n, s->inverse) & (n - 1)] = j;
189
            }
190
        }
191
    }
192
325
}
193
194
3629
av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse)
195
{
196
    int i, j, n;
197
198
3629
    s->revtab = NULL;
199
3629
    s->revtab32 = NULL;
200
201

3629
    if (nbits < 2 || nbits > 17)
202
        goto fail;
203
3629
    s->nbits = nbits;
204
3629
    n = 1 << nbits;
205
206
3629
    if (nbits <= 16) {
207
3629
        s->revtab = av_malloc(n * sizeof(uint16_t));
208
3629
        if (!s->revtab)
209
            goto fail;
210
    } else {
211
        s->revtab32 = av_malloc(n * sizeof(uint32_t));
212
        if (!s->revtab32)
213
            goto fail;
214
    }
215
3629
    s->tmp_buf = av_malloc(n * sizeof(FFTComplex));
216
3629
    if (!s->tmp_buf)
217
        goto fail;
218
3629
    s->inverse = inverse;
219
3629
    s->fft_permutation = FF_FFT_PERM_DEFAULT;
220
221
3629
    s->fft_permute = fft_permute_c;
222
3629
    s->fft_calc    = fft_calc_c;
223
#if CONFIG_MDCT
224
3629
    s->imdct_calc  = ff_imdct_calc_c;
225
3629
    s->imdct_half  = ff_imdct_half_c;
226
3629
    s->mdct_calc   = ff_mdct_calc_c;
227
#endif
228
229
#if FFT_FIXED_32
230
188
    ff_fft_lut_init();
231
#else /* FFT_FIXED_32 */
232
#if FFT_FLOAT
233
    if (ARCH_AARCH64) ff_fft_init_aarch64(s);
234
    if (ARCH_ARM)     ff_fft_init_arm(s);
235
    if (ARCH_PPC)     ff_fft_init_ppc(s);
236
3441
    if (ARCH_X86)     ff_fft_init_x86(s);
237
    if (HAVE_MIPSFPU) ff_fft_init_mips(s);
238
#endif
239
13856
    for(j=4; j<=nbits; j++) {
240
10415
        ff_init_ff_cos_tabs(j);
241
    }
242
#endif /* FFT_FIXED_32 */
243
244
245
3441
    if (ARCH_X86 && FFT_FLOAT && s->fft_permutation == FF_FFT_PERM_AVX) {
246
325
        fft_perm_avx(s);
247
    } else {
248
#define PROCESS_FFT_PERM_SWAP_LSBS(num) do {\
249
    for(i = 0; i < n; i++) {\
250
        int k;\
251
        j = i;\
252
        j = (j & ~3) | ((j >> 1) & 1) | ((j << 1) & 2);\
253
        k = -split_radix_permutation(i, n, s->inverse) & (n - 1);\
254
        s->revtab##num[k] = j;\
255
    } \
256
} while(0);
257
258
#define PROCESS_FFT_PERM_DEFAULT(num) do {\
259
    for(i = 0; i < n; i++) {\
260
        int k;\
261
        j = i;\
262
        k = -split_radix_permutation(i, n, s->inverse) & (n - 1);\
263
        s->revtab##num[k] = j;\
264
    } \
265
} while(0);
266
267
#define SPLIT_RADIX_PERMUTATION(num) do { \
268
    if (s->fft_permutation == FF_FFT_PERM_SWAP_LSBS) {\
269
        PROCESS_FFT_PERM_SWAP_LSBS(num) \
270
    } else {\
271
        PROCESS_FFT_PERM_DEFAULT(num) \
272
    }\
273
} while(0);
274
275
3304
    if (s->revtab)
276

699624
        SPLIT_RADIX_PERMUTATION()
277
3304
    if (s->revtab32)
278
        SPLIT_RADIX_PERMUTATION(32)
279
280
#undef PROCESS_FFT_PERM_DEFAULT
281
#undef PROCESS_FFT_PERM_SWAP_LSBS
282
#undef SPLIT_RADIX_PERMUTATION
283
    }
284
285
3629
    return 0;
286
 fail:
287
    av_freep(&s->revtab);
288
    av_freep(&s->revtab32);
289
    av_freep(&s->tmp_buf);
290
    return -1;
291
}
292
293
48062
static void fft_permute_c(FFTContext *s, FFTComplex *z)
294
{
295
    int j, np;
296
48062
    const uint16_t *revtab = s->revtab;
297
48062
    const uint32_t *revtab32 = s->revtab32;
298
48062
    np = 1 << s->nbits;
299
    /* TODO: handle split-radix permute in a more optimal way, probably in-place */
300
48062
    if (revtab) {
301
12905982
        for(j=0;j<np;j++) s->tmp_buf[revtab[j]] = z[j];
302
    } else
303
        for(j=0;j<np;j++) s->tmp_buf[revtab32[j]] = z[j];
304
305
48062
    memcpy(z, s->tmp_buf, np * sizeof(FFTComplex));
306
48062
}
307
308
3723
av_cold void ff_fft_end(FFTContext *s)
309
{
310
3723
    av_freep(&s->revtab);
311
3723
    av_freep(&s->revtab32);
312
3723
    av_freep(&s->tmp_buf);
313
3723
}
314
315
#if FFT_FIXED_32
316
317
770822
static void fft_calc_c(FFTContext *s, FFTComplex *z) {
318
319
    int nbits, i, n, num_transforms, offset, step;
320
    int n4, n2, n34;
321
    unsigned tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp8;
322
    FFTComplex *tmpz;
323
770822
    const int fft_size = (1 << s->nbits);
324
    int64_t accu;
325
326
770822
    num_transforms = (0x2aab >> (16 - s->nbits)) | 1;
327
328
6613534
    for (n=0; n<num_transforms; n++){
329
5842712
        offset = ff_fft_offsets_lut[n] << 2;
330
5842712
        tmpz = z + offset;
331
332
5842712
        tmp1 = tmpz[0].re + (unsigned)tmpz[1].re;
333
5842712
        tmp5 = tmpz[2].re + (unsigned)tmpz[3].re;
334
5842712
        tmp2 = tmpz[0].im + (unsigned)tmpz[1].im;
335
5842712
        tmp6 = tmpz[2].im + (unsigned)tmpz[3].im;
336
5842712
        tmp3 = tmpz[0].re - (unsigned)tmpz[1].re;
337
5842712
        tmp8 = tmpz[2].im - (unsigned)tmpz[3].im;
338
5842712
        tmp4 = tmpz[0].im - (unsigned)tmpz[1].im;
339
5842712
        tmp7 = tmpz[2].re - (unsigned)tmpz[3].re;
340
341
5842712
        tmpz[0].re = tmp1 + tmp5;
342
5842712
        tmpz[2].re = tmp1 - tmp5;
343
5842712
        tmpz[0].im = tmp2 + tmp6;
344
5842712
        tmpz[2].im = tmp2 - tmp6;
345
5842712
        tmpz[1].re = tmp3 + tmp8;
346
5842712
        tmpz[3].re = tmp3 - tmp8;
347
5842712
        tmpz[1].im = tmp4 - tmp7;
348
5842712
        tmpz[3].im = tmp4 + tmp7;
349
    }
350
351
770822
    if (fft_size < 8)
352
1
        return;
353
354
770821
    num_transforms = (num_transforms >> 1) | 1;
355
356
4059972
    for (n=0; n<num_transforms; n++){
357
3289151
        offset = ff_fft_offsets_lut[n] << 3;
358
3289151
        tmpz = z + offset;
359
360
3289151
        tmp1 = tmpz[4].re + (unsigned)tmpz[5].re;
361
3289151
        tmp3 = tmpz[6].re + (unsigned)tmpz[7].re;
362
3289151
        tmp2 = tmpz[4].im + (unsigned)tmpz[5].im;
363
3289151
        tmp4 = tmpz[6].im + (unsigned)tmpz[7].im;
364
3289151
        tmp5 = tmp1 + tmp3;
365
3289151
        tmp7 = tmp1 - tmp3;
366
3289151
        tmp6 = tmp2 + tmp4;
367
3289151
        tmp8 = tmp2 - tmp4;
368
369
3289151
        tmp1 = tmpz[4].re - (unsigned)tmpz[5].re;
370
3289151
        tmp2 = tmpz[4].im - (unsigned)tmpz[5].im;
371
3289151
        tmp3 = tmpz[6].re - (unsigned)tmpz[7].re;
372
3289151
        tmp4 = tmpz[6].im - (unsigned)tmpz[7].im;
373
374
3289151
        tmpz[4].re = tmpz[0].re - tmp5;
375
3289151
        tmpz[0].re = tmpz[0].re + tmp5;
376
3289151
        tmpz[4].im = tmpz[0].im - tmp6;
377
3289151
        tmpz[0].im = tmpz[0].im + tmp6;
378
3289151
        tmpz[6].re = tmpz[2].re - tmp8;
379
3289151
        tmpz[2].re = tmpz[2].re + tmp8;
380
3289151
        tmpz[6].im = tmpz[2].im + tmp7;
381
3289151
        tmpz[2].im = tmpz[2].im - tmp7;
382
383
3289151
        accu = (int64_t)Q31(M_SQRT1_2)*(int)(tmp1 + tmp2);
384
3289151
        tmp5 = (int32_t)((accu + 0x40000000) >> 31);
385
3289151
        accu = (int64_t)Q31(M_SQRT1_2)*(int)(tmp3 - tmp4);
386
3289151
        tmp7 = (int32_t)((accu + 0x40000000) >> 31);
387
3289151
        accu = (int64_t)Q31(M_SQRT1_2)*(int)(tmp2 - tmp1);
388
3289151
        tmp6 = (int32_t)((accu + 0x40000000) >> 31);
389
3289151
        accu = (int64_t)Q31(M_SQRT1_2)*(int)(tmp3 + tmp4);
390
3289151
        tmp8 = (int32_t)((accu + 0x40000000) >> 31);
391
3289151
        tmp1 = tmp5 + tmp7;
392
3289151
        tmp3 = tmp5 - tmp7;
393
3289151
        tmp2 = tmp6 + tmp8;
394
3289151
        tmp4 = tmp6 - tmp8;
395
396
3289151
        tmpz[5].re = tmpz[1].re - tmp1;
397
3289151
        tmpz[1].re = tmpz[1].re + tmp1;
398
3289151
        tmpz[5].im = tmpz[1].im - tmp2;
399
3289151
        tmpz[1].im = tmpz[1].im + tmp2;
400
3289151
        tmpz[7].re = tmpz[3].re - tmp4;
401
3289151
        tmpz[3].re = tmpz[3].re + tmp4;
402
3289151
        tmpz[7].im = tmpz[3].im + tmp3;
403
3289151
        tmpz[3].im = tmpz[3].im - tmp3;
404
    }
405
406
770821
    step = 1 << ((MAX_LOG2_NFFT-4) - 4);
407
770821
    n4 = 4;
408
409
2441198
    for (nbits=4; nbits<=s->nbits; nbits++){
410
1670377
        n2  = 2*n4;
411
1670377
        n34 = 3*n4;
412
1670377
        num_transforms = (num_transforms >> 1) | 1;
413
414
4206322
        for (n=0; n<num_transforms; n++){
415
2535945
            const FFTSample *w_re_ptr = ff_w_tab_sr + step;
416
2535945
            const FFTSample *w_im_ptr = ff_w_tab_sr + MAX_FFT_SIZE/(4*16) - step;
417
2535945
            offset = ff_fft_offsets_lut[n] << nbits;
418
2535945
            tmpz = z + offset;
419
420
2535945
            tmp5 = tmpz[ n2].re + (unsigned)tmpz[n34].re;
421
2535945
            tmp1 = tmpz[ n2].re - (unsigned)tmpz[n34].re;
422
2535945
            tmp6 = tmpz[ n2].im + (unsigned)tmpz[n34].im;
423
2535945
            tmp2 = tmpz[ n2].im - (unsigned)tmpz[n34].im;
424
425
2535945
            tmpz[ n2].re = tmpz[ 0].re - tmp5;
426
2535945
            tmpz[  0].re = tmpz[ 0].re + tmp5;
427
2535945
            tmpz[ n2].im = tmpz[ 0].im - tmp6;
428
2535945
            tmpz[  0].im = tmpz[ 0].im + tmp6;
429
2535945
            tmpz[n34].re = tmpz[n4].re - tmp2;
430
2535945
            tmpz[ n4].re = tmpz[n4].re + tmp2;
431
2535945
            tmpz[n34].im = tmpz[n4].im + tmp1;
432
2535945
            tmpz[ n4].im = tmpz[n4].im - tmp1;
433
434
21618072
            for (i=1; i<n4; i++){
435
19082127
                FFTSample w_re = w_re_ptr[0];
436
19082127
                FFTSample w_im = w_im_ptr[0];
437
19082127
                accu  = (int64_t)w_re*tmpz[ n2+i].re;
438
19082127
                accu += (int64_t)w_im*tmpz[ n2+i].im;
439
19082127
                tmp1 = (int32_t)((accu + 0x40000000) >> 31);
440
19082127
                accu  = (int64_t)w_re*tmpz[ n2+i].im;
441
19082127
                accu -= (int64_t)w_im*tmpz[ n2+i].re;
442
19082127
                tmp2 = (int32_t)((accu + 0x40000000) >> 31);
443
19082127
                accu  = (int64_t)w_re*tmpz[n34+i].re;
444
19082127
                accu -= (int64_t)w_im*tmpz[n34+i].im;
445
19082127
                tmp3 = (int32_t)((accu + 0x40000000) >> 31);
446
19082127
                accu  = (int64_t)w_re*tmpz[n34+i].im;
447
19082127
                accu += (int64_t)w_im*tmpz[n34+i].re;
448
19082127
                tmp4 = (int32_t)((accu + 0x40000000) >> 31);
449
450
19082127
                tmp5 = tmp1 + tmp3;
451
19082127
                tmp1 = tmp1 - tmp3;
452
19082127
                tmp6 = tmp2 + tmp4;
453
19082127
                tmp2 = tmp2 - tmp4;
454
455
19082127
                tmpz[ n2+i].re = tmpz[   i].re - tmp5;
456
19082127
                tmpz[    i].re = tmpz[   i].re + tmp5;
457
19082127
                tmpz[ n2+i].im = tmpz[   i].im - tmp6;
458
19082127
                tmpz[    i].im = tmpz[   i].im + tmp6;
459
19082127
                tmpz[n34+i].re = tmpz[n4+i].re - tmp2;
460
19082127
                tmpz[ n4+i].re = tmpz[n4+i].re + tmp2;
461
19082127
                tmpz[n34+i].im = tmpz[n4+i].im + tmp1;
462
19082127
                tmpz[ n4+i].im = tmpz[n4+i].im - tmp1;
463
464
19082127
                w_re_ptr += step;
465
19082127
                w_im_ptr -= step;
466
            }
467
        }
468
1670377
        step >>= 1;
469
1670377
        n4   <<= 1;
470
    }
471
}
472
473
#else /* FFT_FIXED_32 */
474
475
#define BUTTERFLIES(a0,a1,a2,a3) {\
476
    BF(t3, t5, t5, t1);\
477
    BF(a2.re, a0.re, a0.re, t5);\
478
    BF(a3.im, a1.im, a1.im, t3);\
479
    BF(t4, t6, t2, t6);\
480
    BF(a3.re, a1.re, a1.re, t4);\
481
    BF(a2.im, a0.im, a0.im, t6);\
482
}
483
484
// force loading all the inputs before storing any.
485
// this is slightly slower for small data, but avoids store->load aliasing
486
// for addresses separated by large powers of 2.
487
#define BUTTERFLIES_BIG(a0,a1,a2,a3) {\
488
    FFTSample r0=a0.re, i0=a0.im, r1=a1.re, i1=a1.im;\
489
    BF(t3, t5, t5, t1);\
490
    BF(a2.re, a0.re, r0, t5);\
491
    BF(a3.im, a1.im, i1, t3);\
492
    BF(t4, t6, t2, t6);\
493
    BF(a3.re, a1.re, r1, t4);\
494
    BF(a2.im, a0.im, i0, t6);\
495
}
496
497
#define TRANSFORM(a0,a1,a2,a3,wre,wim) {\
498
    CMUL(t1, t2, a2.re, a2.im, wre, -wim);\
499
    CMUL(t5, t6, a3.re, a3.im, wre,  wim);\
500
    BUTTERFLIES(a0,a1,a2,a3)\
501
}
502
503
#define TRANSFORM_ZERO(a0,a1,a2,a3) {\
504
    t1 = a2.re;\
505
    t2 = a2.im;\
506
    t5 = a3.re;\
507
    t6 = a3.im;\
508
    BUTTERFLIES(a0,a1,a2,a3)\
509
}
510
511
/* z[0...8n-1], w[1...2n-1] */
512
#define PASS(name)\
513
static void name(FFTComplex *z, const FFTSample *wre, unsigned int n)\
514
{\
515
    FFTDouble t1, t2, t3, t4, t5, t6;\
516
    int o1 = 2*n;\
517
    int o2 = 4*n;\
518
    int o3 = 6*n;\
519
    const FFTSample *wim = wre+o1;\
520
    n--;\
521
\
522
    TRANSFORM_ZERO(z[0],z[o1],z[o2],z[o3]);\
523
    TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1]);\
524
    do {\
525
        z += 2;\
526
        wre += 2;\
527
        wim -= 2;\
528
        TRANSFORM(z[0],z[o1],z[o2],z[o3],wre[0],wim[0]);\
529
        TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1]);\
530
    } while(--n);\
531
}
532
533
25751553
PASS(pass)
534
#if !CONFIG_SMALL
535
#undef BUTTERFLIES
536
#define BUTTERFLIES BUTTERFLIES_BIG
537
3063261
PASS(pass_big)
538
#endif
539
540
#define DECL_FFT(n,n2,n4)\
541
static void fft##n(FFTComplex *z)\
542
{\
543
    fft##n2(z);\
544
    fft##n4(z+n4*2);\
545
    fft##n4(z+n4*3);\
546
    pass(z,FFT_NAME(ff_cos_##n),n4/2);\
547
}
548
549
18923667
static void fft4(FFTComplex *z)
550
{
551
    FFTDouble t1, t2, t3, t4, t5, t6, t7, t8;
552
553
18923667
    BF(t3, t1, z[0].re, z[1].re);
554
18923667
    BF(t8, t6, z[3].re, z[2].re);
555
18923667
    BF(z[2].re, z[0].re, t1, t6);
556
18923667
    BF(t4, t2, z[0].im, z[1].im);
557
18923667
    BF(t7, t5, z[2].im, z[3].im);
558
18923667
    BF(z[3].im, z[1].im, t4, t8);
559
18923667
    BF(z[3].re, z[1].re, t3, t7);
560
18923667
    BF(z[2].im, z[0].im, t2, t5);
561
18923667
}
562
563
9629387
static void fft8(FFTComplex *z)
564
{
565
    FFTDouble t1, t2, t3, t4, t5, t6;
566
567
9629387
    fft4(z);
568
569
9629387
    BF(t1, z[5].re, z[4].re, -z[5].re);
570
9629387
    BF(t2, z[5].im, z[4].im, -z[5].im);
571
9629387
    BF(t5, z[7].re, z[6].re, -z[7].re);
572
9629387
    BF(t6, z[7].im, z[6].im, -z[7].im);
573
574
9629387
    BUTTERFLIES(z[0],z[2],z[4],z[6]);
575
9629387
    TRANSFORM(z[1],z[3],z[5],z[7],sqrthalf,sqrthalf);
576
9629387
}
577
578
#if !CONFIG_SMALL
579
4135263
static void fft16(FFTComplex *z)
580
{
581
    FFTDouble t1, t2, t3, t4, t5, t6;
582
4135263
    FFTSample cos_16_1 = FFT_NAME(ff_cos_16)[1];
583
4135263
    FFTSample cos_16_3 = FFT_NAME(ff_cos_16)[3];
584
585
4135263
    fft8(z);
586
4135263
    fft4(z+8);
587
4135263
    fft4(z+12);
588
589
4135263
    TRANSFORM_ZERO(z[0],z[4],z[8],z[12]);
590
4135263
    TRANSFORM(z[2],z[6],z[10],z[14],sqrthalf,sqrthalf);
591
4135263
    TRANSFORM(z[1],z[5],z[9],z[13],cos_16_1,cos_16_3);
592
4135263
    TRANSFORM(z[3],z[7],z[11],z[15],cos_16_3,cos_16_1);
593
4135263
}
594
#else
595
DECL_FFT(16,8,4)
596
#endif
597
2593237
DECL_FFT(32,16,8)
598
631435
DECL_FFT(64,32,16)
599
324316
DECL_FFT(128,64,32)
600
114812
DECL_FFT(256,128,64)
601
81395
DECL_FFT(512,256,128)
602
#if !CONFIG_SMALL
603
#define pass pass_big
604
#endif
605
8553
DECL_FFT(1024,512,256)
606
2969
DECL_FFT(2048,1024,512)
607
1008
DECL_FFT(4096,2048,1024)
608
689
DECL_FFT(8192,4096,2048)
609
DECL_FFT(16384,8192,4096)
610
DECL_FFT(32768,16384,8192)
611
DECL_FFT(65536,32768,16384)
612
DECL_FFT(131072,65536,32768)
613
614
static void (* const fft_dispatch[])(FFTComplex*) = {
615
    fft4, fft8, fft16, fft32, fft64, fft128, fft256, fft512, fft1024,
616
    fft2048, fft4096, fft8192, fft16384, fft32768, fft65536, fft131072
617
};
618
619
3136313
static void fft_calc_c(FFTContext *s, FFTComplex *z)
620
{
621
3136313
    fft_dispatch[s->nbits-2](z);
622
3136313
}
623
#endif /* FFT_FIXED_32 */