1 #include <stdatomic.h>
2 #include <inttypes.h>
3 #include <stdio.h>
4
5 #ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
6 _Atomic uint32_t atomic_4;
7 #endif
8 #ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2
9 _Atomic uint16_t atomic_2;
10 #endif
11
12 int
main(void)13 main(void)
14 {
15 int ret = 0;
16 #ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
17 uint32_t zero_4 = 0;
18 if (atomic_compare_exchange_strong(&atomic_4, &zero_4, 1)) {
19 printf("atomic_compare_exchange 4 worked, value %" PRIu32 " zero %" PRIu32 "\n",
20 atomic_4, zero_4);
21 uint32_t old;
22 old = atomic_exchange_explicit(&atomic_4, 0, memory_order_relaxed);
23 if (atomic_4 == 0 && old == 1) {
24 printf("atomic_exchange_explicit 4 worked %" PRIu32 " value now %" PRIu32 "\n",
25 old, atomic_4);
26 } else {
27 printf("atomic_exchange_explicit failed %" PRIu32 " value now %" PRIu32 "\n",
28 old, atomic_4);
29 ret = 1;
30 }
31 } else {
32 printf("atomic_compare_exchange 4 failed, value %" PRIu32 "\n", atomic_4);
33 ret = 1;
34 }
35 #endif
36 #ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2
37 uint16_t zero_2 = 0;
38 if (atomic_compare_exchange_strong(&atomic_2, &zero_2, 1)) {
39 printf("atomic_compare_exchange 2 worked, value %" PRIu16 " zero %" PRIu16 "\n", atomic_2, zero_2);
40 uint16_t old;
41 old = atomic_exchange_explicit(&atomic_2, 0, memory_order_relaxed);
42 if (atomic_2 == 0 && old == 1) {
43 printf("atomic_exchange_explicit 2 worked %" PRIu16 " value now %" PRIu16 "\n",
44 old, atomic_2);
45 } else {
46 printf("atomic_exchange_explicit 2 failed %" PRIu16 " value now %" PRIu16 "\n",
47 old, atomic_2);
48 ret = 1;
49 }
50 } else {
51 printf("atomic_compare_exchange 2 failed, value %" PRIu16 "\n", atomic_2);
52 ret = 1;
53 }
54 #endif
55 return ret;
56 }
57
