add.c.diff

add.c.diff

diff --git a/add/add.c b/add/add.c
index 48f7b17..0d6370c 100644
--- a/add/add.c
+++ b/add/add.c
@@ -16,6 +16,9 @@ long long microseconds() {
 #error define USE_ATOMIC 1 or 0
 #endif

+long x = 1;
+long* y = &x;
+
 static inline long add(long* a, long b) {
     __asm__ __volatile__(
 #if USE_ATOMIC
@@ -25,6 +28,11 @@ static inline long add(long* a, long b) {
         : "+r" (b), "+m" (a)
         :
         : "memory");
+    __asm__ __volatile__(
+        "xadd %0, %1"
+        : "+r" (x), "+m" (y)
+        :
+        : "memory");
     return *a + b;
 }