src/hotspot/share/gc/g1/g1FreeIdSet.cpp

@@ -77,11 +77,11 @@
   uint index;
   while (true) {
     index = head_index(old_head);
     assert(index < _size, "invariant");
     uintx new_head = make_head(_next[index], old_head);
-    new_head = Atomic::cmpxchg(new_head, &_head, old_head);
+    new_head = Atomic::cmpxchg(&_head, old_head, new_head);
     if (new_head == old_head) break;
     old_head = new_head;
   }
   DEBUG_ONLY(_next[index] = Claimed;)
   return _start + index;

@@ -93,11 +93,11 @@
   assert(_next[index] == Claimed, "precondition");
   uintx old_head = Atomic::load(&_head);
   while (true) {
     _next[index] = head_index(old_head);
     uintx new_head = make_head(index, old_head);
-    new_head = Atomic::cmpxchg(new_head, &_head, old_head);
+    new_head = Atomic::cmpxchg(&_head, old_head, new_head);
     if (new_head == old_head) break;
     old_head = new_head;
   }
   // Now that id has been released, permit another thread through the gate.
   _sem.signal();