summaryrefslogtreecommitdiffstats
path: root/libavcodec/i386/fft_sse.c
blob: 175cea506cc453d2546fc1a1b00c2e2849052877 (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
/*
 * FFT/MDCT transform with SSE optimizations
 * Copyright (c) 2002 Fabrice Bellard.
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include "../dsputil.h"
#include <math.h>

#ifdef HAVE_BUILTIN_VECTOR

#include <xmmintrin.h>

static const float p1p1p1m1[4] __attribute__((aligned(16))) = 
    { 1.0, 1.0, 1.0, -1.0 };

static const float p1p1m1p1[4] __attribute__((aligned(16))) = 
    { 1.0, 1.0, -1.0, 1.0 };

static const float p1p1m1m1[4] __attribute__((aligned(16))) = 
    { 1.0, 1.0, -1.0, -1.0 };

#if 0
static void print_v4sf(const char *str, __m128 a)
{
    float *p = (float *)&a;
    printf("%s: %f %f %f %f\n",
           str, p[0], p[1], p[2], p[3]);
}
#endif

/* XXX: handle reverse case */
void fft_calc_sse(FFTContext *s, FFTComplex *z)
{
    int ln = s->nbits;
    int	j, np, np2;
    int	nblocks, nloops;
    register FFTComplex *p, *q;
    FFTComplex *cptr, *cptr1;
    int k;

    np = 1 << ln;

    {
        __m128 *r, a, b, a1, c1, c2;

        r = (__m128 *)&z[0];
        c1 = *(__m128 *)p1p1m1m1;
        c2 = *(__m128 *)p1p1p1m1;
        if (s->inverse)
            c2 = *(__m128 *)p1p1m1p1;
        else
            c2 = *(__m128 *)p1p1p1m1;

        j = (np >> 2);
        do {
            a = r[0];
            b = _mm_shuffle_ps(a, a, _MM_SHUFFLE(1, 0, 3, 2));
            a = _mm_mul_ps(a, c1);
            /* do the pass 0 butterfly */
            a = _mm_add_ps(a, b);

            a1 = r[1];
            b = _mm_shuffle_ps(a1, a1, _MM_SHUFFLE(1, 0, 3, 2));
            a1 = _mm_mul_ps(a1, c1);
            /* do the pass 0 butterfly */
            b = _mm_add_ps(a1, b);

            /* multiply third by -i */
            b = _mm_shuffle_ps(b, b, _MM_SHUFFLE(2, 3, 1, 0));
            b = _mm_mul_ps(b, c2);

            /* do the pass 1 butterfly */
            r[0] = _mm_add_ps(a, b);
            r[1] = _mm_sub_ps(a, b);
            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 {
                __m128 a, b, c, t1, t2;

                a = *(__m128 *)p;
                b = *(__m128 *)q;
                
                /* complex mul */
                c = *(__m128 *)cptr;
                /*  cre*re cim*re */
                t1 = _mm_mul_ps(c, 
                                _mm_shuffle_ps(b, b, _MM_SHUFFLE(2, 2, 0, 0))); 
                c = *(__m128 *)(cptr + 2);
                /*  -cim*im cre*im */
                t2 = _mm_mul_ps(c,
                                _mm_shuffle_ps(b, b, _MM_SHUFFLE(3, 3, 1, 1))); 
                b = _mm_add_ps(t1, t2);
                
                /* butterfly */
                *(__m128 *)p = _mm_add_ps(a, b);
                *(__m128 *)q = _mm_sub_ps(a, b);
                
                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);
}

#endif
OpenPOWER on IntegriCloud