--- a/src/hotspot/share/gc/shared/referenceProcessorPhaseTimes.cpp	Mon Nov 25 12:30:24 2019 +0100
+++ b/src/hotspot/share/gc/shared/referenceProcessorPhaseTimes.cpp	Mon Nov 25 12:31:39 2019 +0100
@@ -246,7 +246,7 @@
 
 void ReferenceProcessorPhaseTimes::add_ref_cleared(ReferenceType ref_type, size_t count) {
   ASSERT_REF_TYPE(ref_type);
-  Atomic::add(count, &_ref_cleared[ref_type_2_index(ref_type)]);
+  Atomic::add(&_ref_cleared[ref_type_2_index(ref_type)], count);
 }
 
 void ReferenceProcessorPhaseTimes::set_ref_discovered(ReferenceType ref_type, size_t count) {