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
|
/*
* FFT/IFFT transforms
* AltiVec-enabled
* Copyright (c) 2003 Romain Dolbeau <romain@dolbeau.org>
* Based on code Copyright (c) 2002 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavcodec/dsputil.h"
#include "dsputil_ppc.h"
#include "util_altivec.h"
/**
* Do a complex FFT with the parameters defined in ff_fft_init(). The
* input data must be permuted before with s->revtab table. No
* 1.0/sqrt(n) normalization is done.
* AltiVec-enabled
* This code assumes that the 'z' pointer is 16 bytes-aligned
* It also assumes all FFTComplex are 8 bytes-aligned pair of float
* The code is exactly the same as the SSE version, except
* that successive MUL + ADD/SUB have been merged into
* fused multiply-add ('vec_madd' in altivec)
*/
void ff_fft_calc_altivec(FFTContext *s, FFTComplex *z)
{
POWERPC_PERF_DECLARE(altivec_fft_num, s->nbits >= 6);
register const vector float vczero = (const vector float)vec_splat_u32(0.);
int ln = s->nbits;
int j, np, np2;
int nblocks, nloops;
register FFTComplex *p, *q;
FFTComplex *cptr, *cptr1;
int k;
POWERPC_PERF_START_COUNT(altivec_fft_num, s->nbits >= 6);
np = 1 << ln;
{
vector float *r, a, b, a1, c1, c2;
r = (vector float *)&z[0];
c1 = vcii(p,p,n,n);
if (s->inverse) {
c2 = vcii(p,p,n,p);
} else {
c2 = vcii(p,p,p,n);
}
j = (np >> 2);
do {
a = vec_ld(0, r);
a1 = vec_ld(sizeof(vector float), r);
b = vec_perm(a,a,vcprmle(1,0,3,2));
a = vec_madd(a,c1,b);
/* do the pass 0 butterfly */
b = vec_perm(a1,a1,vcprmle(1,0,3,2));
b = vec_madd(a1,c1,b);
/* do the pass 0 butterfly */
/* multiply third by -i */
b = vec_perm(b,b,vcprmle(2,3,1,0));
/* do the pass 1 butterfly */
vec_st(vec_madd(b,c2,a), 0, r);
vec_st(vec_nmsub(b,c2,a), sizeof(vector float), r);
r += 2;
} while (--j != 0);
}
/* pass 2 .. ln-1 */
nblocks = np >> 3;
nloops = 1 << 2;
np2 = np >> 1;
cptr1 = s->exptab1;
do {
p = z;
q = z + nloops;
j = nblocks;
do {
cptr = cptr1;
k = nloops >> 1;
do {
vector float a,b,c,t1;
a = vec_ld(0, (float*)p);
b = vec_ld(0, (float*)q);
/* complex mul */
c = vec_ld(0, (float*)cptr);
/* cre*re cim*re */
t1 = vec_madd(c, vec_perm(b,b,vcprmle(2,2,0,0)),vczero);
c = vec_ld(sizeof(vector float), (float*)cptr);
/* -cim*im cre*im */
b = vec_madd(c, vec_perm(b,b,vcprmle(3,3,1,1)),t1);
/* butterfly */
vec_st(vec_add(a,b), 0, (float*)p);
vec_st(vec_sub(a,b), 0, (float*)q);
p += 2;
q += 2;
cptr += 4;
} while (--k);
p += nloops;
q += nloops;
} while (--j);
cptr1 += nloops * 2;
nblocks = nblocks >> 1;
nloops = nloops << 1;
} while (nblocks != 0);
POWERPC_PERF_STOP_COUNT(altivec_fft_num, s->nbits >= 6);
}
|
