-# See if 64-bit atomic operations are supported.
-# Note that without __atomic builtins, we can only
-# assume atomic loads/stores max at pointer size.
-config_host_data.set('CONFIG_ATOMIC64', cc.links('''
+atomic_test = '''
#include <stdint.h>
int main(void)
{
- uint64_t x = 0, y = 0;
+ @0@ x = 0, y = 0;
y = __atomic_load_n(&x, __ATOMIC_RELAXED);
__atomic_store_n(&x, y, __ATOMIC_RELAXED);
__atomic_compare_exchange_n(&x, &y, x, 0, __ATOMIC_RELAXED,
__ATOMIC_RELAXED);
__atomic_exchange_n(&x, y, __ATOMIC_RELAXED);
__atomic_fetch_add(&x, y, __ATOMIC_RELAXED);
return 0;
- }'''))
+ }'''
+
+# See if 64-bit atomic operations are supported.
+# Note that without __atomic builtins, we can only
+# assume atomic loads/stores max at pointer size.
+config_host_data.set('CONFIG_ATOMIC64',
cc.links(atomic_test.format('uint64_t')))
has_int128 = cc.links('''
__int128_t a;
@@ -1837,15 +1839,10 @@ has_int128 = cc.links('''
config_host_data.set('CONFIG_INT128', has_int128)
if has_int128
- has_atomic128 = cc.links('''
- int main(void)
- {
- unsigned __int128 x = 0, y = 0;
- y = __atomic_load(&x, 0);
- __atomic_store(&x, y, 0);
- __atomic_compare_exchange(&x, &y, x, 0, 0, 0);
- return 0;
- }''')
+ # "do we have 128-bit atomics which are handled inline and specifically not
+ # via libatomic". The reason we can't use libatomic is documented in the
+ # comment starting "GCC is a house divided" in include/qemu/atomic128.h.
+ has_atomic128 = cc.links(atomic_test.format('unsigned __int128'))