Use __sync_swap when available.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/memory.cc b/src/memory.cc
index a5eb3e9..027bc3f 100644
--- a/src/memory.cc
+++ b/src/memory.cc
@@ -11,6 +11,10 @@
 #include <stdlib.h>
 #include "stdexcept.h"
 
+#if !__has_builtin(__sync_swap)
+#define __sync_swap __sync_lock_test_and_set
+#endif
+
 namespace std
 {
 	struct nothrow_t {};
@@ -33,7 +37,7 @@ namespace std
 	__attribute__((weak))
 	new_handler set_new_handler(new_handler handler)
 	{
-		return __sync_lock_test_and_set(&new_handl, handler);
+		return __sync_swap(&new_handl, handler);
 	}
 }