1 /* Test that __builtin_prefetch does no harm.
2 
3    Data prefetch should not fault if used with an invalid address.  */
4 
5 #include <limits.h>
6 
7 #define ARRSIZE 65
8 int *bad_addr[ARRSIZE];
9 int arr_used;
10 
11 /* Fill bad_addr with a range of values in the hopes that on any target
12    some will be invalid addresses.  */
13 void
init_addrs(void)14 init_addrs (void)
15 {
16   int i;
17   int bits_per_ptr = sizeof (void *) * 8;
18   for (i = 0; i < bits_per_ptr; i++)
19     bad_addr[i] = (void *)(1UL << i);
20   arr_used = bits_per_ptr + 1;  /* The last element used is zero.  */
21 }
22 
23 void
prefetch_for_read(void)24 prefetch_for_read (void)
25 {
26   int i;
27   for (i = 0; i < ARRSIZE; i++)
28     __builtin_prefetch (bad_addr[i], 0, 0);
29 }
30 
31 void
prefetch_for_write(void)32 prefetch_for_write (void)
33 {
34   int i;
35   for (i = 0; i < ARRSIZE; i++)
36     __builtin_prefetch (bad_addr[i], 1, 0);
37 }
38 
39 int
main()40 main ()
41 {
42   init_addrs ();
43   prefetch_for_read ();
44   prefetch_for_write ();
45   exit (0);
46 }
47