new generic FFT/MDCT code for audio codecs
[libav.git] / libavcodec / i386 / fft_sse.c
CommitLineData
bb6f5690
FB
1/*
2 * FFT/MDCT transform with SSE optimizations
3 * Copyright (c) 2002 Fabrice Bellard.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19#include "../dsputil.h"
20#include <math.h>
21
22#include <xmmintrin.h>
23
24static const float p1p1p1m1[4] __attribute__((aligned(16))) =
25 { 1.0, 1.0, 1.0, -1.0 };
26
27static const float p1p1m1m1[4] __attribute__((aligned(16))) =
28 { 1.0, 1.0, -1.0, -1.0 };
29
30#if 0
31static void print_v4sf(const char *str, __m128 a)
32{
33 float *p = (float *)&a;
34 printf("%s: %f %f %f %f\n",
35 str, p[0], p[1], p[2], p[3]);
36}
37#endif
38
39/* XXX: handle reverse case */
40void fft_calc_sse(FFTContext *s, FFTComplex *z)
41{
42 int ln = s->nbits;
43 int j, np, np2;
44 int nblocks, nloops;
45 register FFTComplex *p, *q;
46 FFTComplex *cptr, *cptr1;
47 int k;
48
49 np = 1 << ln;
50
51 {
52 __m128 *r, a, b, a1, c1, c2;
53
54 r = (__m128 *)&z[0];
55 c1 = *(__m128 *)p1p1m1m1;
56 c2 = *(__m128 *)p1p1p1m1;
57 j = (np >> 2);
58 do {
59 a = r[0];
60 b = _mm_shuffle_ps(a, a, _MM_SHUFFLE(1, 0, 3, 2));
61 a = _mm_mul_ps(a, c1);
62 /* do the pass 0 butterfly */
63 a = _mm_add_ps(a, b);
64
65 a1 = r[1];
66 b = _mm_shuffle_ps(a1, a1, _MM_SHUFFLE(1, 0, 3, 2));
67 a1 = _mm_mul_ps(a1, c1);
68 /* do the pass 0 butterfly */
69 b = _mm_add_ps(a1, b);
70
71 /* multiply third by -i */
72 b = _mm_shuffle_ps(b, b, _MM_SHUFFLE(2, 3, 1, 0));
73 b = _mm_mul_ps(b, c2);
74
75 /* do the pass 1 butterfly */
76 r[0] = _mm_add_ps(a, b);
77 r[1] = _mm_sub_ps(a, b);
78 r += 2;
79 } while (--j != 0);
80 }
81 /* pass 2 .. ln-1 */
82
83 nblocks = np >> 3;
84 nloops = 1 << 2;
85 np2 = np >> 1;
86
87 cptr1 = s->exptab1;
88 do {
89 p = z;
90 q = z + nloops;
91 j = nblocks;
92 do {
93 cptr = cptr1;
94 k = nloops >> 1;
95 do {
96 __m128 a, b, c, t1, t2;
97
98 a = *(__m128 *)p;
99 b = *(__m128 *)q;
100
101 /* complex mul */
102 c = *(__m128 *)cptr;
103 /* cre*re cim*re */
104 t1 = _mm_mul_ps(c,
105 _mm_shuffle_ps(b, b, _MM_SHUFFLE(2, 2, 0, 0)));
106 c = *(__m128 *)(cptr + 2);
107 /* -cim*im cre*im */
108 t2 = _mm_mul_ps(c,
109 _mm_shuffle_ps(b, b, _MM_SHUFFLE(3, 3, 1, 1)));
110 b = _mm_add_ps(t1, t2);
111
112 /* butterfly */
113 *(__m128 *)p = _mm_add_ps(a, b);
114 *(__m128 *)q = _mm_sub_ps(a, b);
115
116 p += 2;
117 q += 2;
118 cptr += 4;
119 } while (--k);
120
121 p += nloops;
122 q += nloops;
123 } while (--j);
124 cptr1 += nloops * 2;
125 nblocks = nblocks >> 1;
126 nloops = nloops << 1;
127 } while (nblocks != 0);
128}