--- old/src/hotspot/share/gc/z/zBitMap.inline.hpp	2019-11-21 11:55:16.449058596 +0100
+++ new/src/hotspot/share/gc/z/zBitMap.inline.hpp	2019-11-21 11:55:16.193054268 +0100
@@ -55,7 +55,7 @@
       inc_live = false;
       return false;
     }
-    const bm_word_t cur_val = Atomic::cmpxchg(new_val, addr, old_val);
+    const bm_word_t cur_val = Atomic::cmpxchg(addr, old_val, new_val);
     if (cur_val == old_val) {
       // Success
       const bm_word_t marked_mask = bit_mask(bit);