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
|
/*
Copyright (C) 2007 Paul sDavis
Written by Sampo Savolainen
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <xmmintrin.h>
void
x86_sse_find_peaks(float *buf, unsigned nframes, float *min, float *max)
{
__m128 current_max, current_min, work;
// Load max and min values into all four slots of the XMM registers
current_min = _mm_set1_ps(*min);
current_max = _mm_set1_ps(*max);
// Work input until "buf" reaches 16 byte alignment
while ( ((unsigned long)buf) % 16 != 0 && nframes > 0) {
// Load the next float into the work buffer
work = _mm_set1_ps(*buf);
current_min = _mm_min_ps(current_min, work);
current_max = _mm_max_ps(current_max, work);
buf++;
nframes--;
}
// use 64 byte prefetch for quadruple quads
while (nframes >= 16) {
__builtin_prefetch(buf+64,0,0);
work = _mm_load_ps(buf);
current_min = _mm_min_ps(current_min, work);
current_max = _mm_max_ps(current_max, work);
buf+=4;
work = _mm_load_ps(buf);
current_min = _mm_min_ps(current_min, work);
current_max = _mm_max_ps(current_max, work);
buf+=4;
work = _mm_load_ps(buf);
current_min = _mm_min_ps(current_min, work);
current_max = _mm_max_ps(current_max, work);
buf+=4;
work = _mm_load_ps(buf);
current_min = _mm_min_ps(current_min, work);
current_max = _mm_max_ps(current_max, work);
buf+=4;
nframes-=16;
}
// work through aligned buffers
while (nframes >= 4) {
work = _mm_load_ps(buf);
current_min = _mm_min_ps(current_min, work);
current_max = _mm_max_ps(current_max, work);
buf+=4;
nframes-=4;
}
// work through the rest < 4 samples
while ( nframes > 0) {
// Load the next float into the work buffer
work = _mm_set1_ps(*buf);
current_min = _mm_min_ps(current_min, work);
current_max = _mm_max_ps(current_max, work);
buf++;
nframes--;
}
// Find min & max value in current_max through shuffle tricks
work = current_min;
work = _mm_shuffle_ps(work, work, _MM_SHUFFLE(2, 3, 0, 1));
work = _mm_min_ps (work, current_min);
current_min = work;
work = _mm_shuffle_ps(work, work, _MM_SHUFFLE(1, 0, 3, 2));
work = _mm_min_ps (work, current_min);
_mm_store_ss(min, work);
work = current_max;
work = _mm_shuffle_ps(work, work, _MM_SHUFFLE(2, 3, 0, 1));
work = _mm_max_ps (work, current_max);
current_max = work;
work = _mm_shuffle_ps(work, work, _MM_SHUFFLE(1, 0, 3, 2));
work = _mm_max_ps (work, current_max);
_mm_store_ss(max, work);
}
|
