blob: f643c5c7286349b6a394da6a76612c2908cc04e1 (
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
|
/* Test that __builtin_prefetch does no harm.
Data prefetch should not fault if used with an invalid address. */
#include <limits.h>
#define ARRSIZE 65
int *bad_addr[ARRSIZE];
int arr_used;
/* Fill bad_addr with a range of values in the hopes that on any target
some will be invalid addresses. */
void
init_addrs (void)
{
int i;
int bits_per_ptr = sizeof (void *) * 8;
for (i = 0; i < bits_per_ptr; i++)
bad_addr[i] = (void *)(1UL << i);
arr_used = bits_per_ptr + 1; /* The last element used is zero. */
}
void
prefetch_for_read (void)
{
int i;
for (i = 0; i < ARRSIZE; i++)
__builtin_prefetch (bad_addr[i], 0, 0);
}
void
prefetch_for_write (void)
{
int i;
for (i = 0; i < ARRSIZE; i++)
__builtin_prefetch (bad_addr[i], 1, 0);
}
int
main ()
{
init_addrs ();
prefetch_for_read ();
prefetch_for_write ();
exit (0);
}
|
