--- old/src/hotspot/share/gc/shared/stringdedup/stringDedupQueue.cpp	2019-11-21 11:53:05.454857093 +0100
+++ new/src/hotspot/share/gc/shared/stringdedup/stringDedupQueue.cpp	2019-11-21 11:53:05.198852911 +0100
@@ -32,7 +32,7 @@
 volatile size_t   StringDedupQueue::_claimed_index = 0;
 
 size_t StringDedupQueue::claim() {
-  return Atomic::add(size_t(1), &_claimed_index) - 1;
+  return Atomic::add(&_claimed_index, size_t(1)) - 1;
 }
 
 void StringDedupQueue::unlink_or_oops_do(StringDedupUnlinkOrOopsDoClosure* cl) {