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
|
#include <stdio.h>
#include <stdint.h>
#include <time.h>
#include <string.h>
#include "../alpha_mmintrin.h"
#define ITERATIONS 10000
int main(int argc, char ** argv) {
uint64_t a[512], b[512], c[512];
uint64_t l1, l2;
uint64_t start, end, overhead;
uint64_t cix_total = 0, noncix_total = 0;
int i, j, count = 0;
start = __rpcc();
end = __rpcc();
overhead = end - start;
srand(time(NULL));
for (i = 0; i < 512; i++) {
a[i] = rand();
}
for (j = 0; j < ITERATIONS; j++) {
start = __rpcc();
for (i = 0; i < 512; i++) {
l1 = a[i];
l2 = 1 << (64 - __ctlz(l1));
b[i] = l2;
}
end = __rpcc();
cix_total += end - start - overhead;
memset(b, 4096, 0);
}
for (j = 0; j < ITERATIONS; j++) {
start = __rpcc();
for (i = 0; i < 512; i++) {
l1 = a[i];
while (l1 != 0) {
l1 >>= 1;
count += 1;
}
l2 = 1 << count;
c[i] = l2;
// printf("nextpow2 of %lu is %lu\n", i, l2);
count = 0;
}
end = __rpcc();
noncix_total += end - start - overhead;
memset(c, 4096, 0);
}
noncix_total /= ITERATIONS;
cix_total /= ITERATIONS;
if (memcmp(b, c, 4096) == 0) {
printf("%s:\n", argv[0]);
printf(" CIX time: %9lu nanoseconds\n non-CIX time: %9lu nanoseconds\n", cix_total, noncix_total);
} else {
puts("Final arrays are not equal. Something happened.");
}
return 0;
}
|
