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
|
#include <sys/mman.h>
#include <sys/stat.h>
#include <err.h>
#include <fcntl.h>
#include <immintrin.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <bsd/stdlib.h>
#define VECWDTH (512 / 8)
static const unsigned char *readfile(const char *, size_t *);
static const uint8_t charmsk[64] = {
0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
};
bool
strisascii(const unsigned char *s, size_t n)
{
__m512i msk = _mm512_loadu_epi8(charmsk);
while (n >= VECWDTH) {
if (_mm512_test_epi8_mask(_mm512_loadu_epi8(s), msk) != 0)
return false;
s += VECWDTH;
n -= VECWDTH;
}
for (size_t i = 0; i < n; i++) {
if (s[i] > 0x7F)
return false;
}
return true;
}
bool
strisascii_dumb(const unsigned char *s, size_t n)
{
for (size_t i = 0; i < n; i++) {
if (s[i] > 0x7F)
return false;
}
return true;
}
int
main(int argc, char **argv)
{
if (argc != 2) {
fprintf(stderr, "Usage: %s file\n", getprogname());
exit(EXIT_FAILURE);
}
size_t len;
int rv = EXIT_SUCCESS;
const unsigned char *beg = readfile(argv[1], &len);
clock_t tmbeg = clock();
if (!strisascii(beg, len))
puts("Non-ASCII");
printf("Elapsed time: %.3fs\n", (double)(clock() - tmbeg) / CLOCKS_PER_SEC);
tmbeg = clock();
if (!strisascii_dumb((const unsigned char *)beg, len))
puts("Non-ASCII");
printf("Elapsed time: %.3fs\n", (double)(clock() - tmbeg) / CLOCKS_PER_SEC);
munmap((void *)beg, len);
return rv;
}
const unsigned char *
readfile(const char *filename, size_t *n)
{
int fd = open(filename, O_RDONLY);
if (fd == -1)
err(1, "open: %s", filename);
struct stat sb;
if (fstat(fd, &sb) == -1)
err(1, "fstat: %s", filename);
*n = sb.st_size;
const unsigned char *p = mmap(NULL, *n, PROT_READ, MAP_PRIVATE, fd, 0);
if (p == MAP_FAILED)
err(1, "mmap: %s", filename);
return p;
}
|
