--- old/src/hotspot/share/gc/shared/space.cpp	2017-10-10 17:31:57.413342704 -0400
+++ new/src/hotspot/share/gc/shared/space.cpp	2017-10-10 17:31:56.959258693 -0400
@@ -631,7 +631,7 @@
     HeapWord* obj = top();
     if (pointer_delta(end(), obj) >= size) {
       HeapWord* new_top = obj + size;
-      HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
+      HeapWord* result = Atomic::cmpxchg(new_top, top_addr(), obj);
       // result can be one of two:
       //  the old top value: the exchange succeeded
       //  otherwise: the new value of the top is returned.