--- a/src/hotspot/share/gc/shenandoah/shenandoahNumberSeq.cpp	Mon Nov 25 12:30:24 2019 +0100
+++ b/src/hotspot/share/gc/shenandoah/shenandoahNumberSeq.cpp	Mon Nov 25 12:31:39 2019 +0100
@@ -132,7 +132,7 @@
 }
 
 void BinaryMagnitudeSeq::add(size_t val) {
-  Atomic::add(val, &_sum);
+  Atomic::add(&_sum, val);
 
   int mag = log2_intptr(val) + 1;
 
@@ -147,7 +147,7 @@
     mag = BitsPerSize_t - 1;
   }
 
-  Atomic::add((size_t)1, &_mags[mag]);
+  Atomic::add(&_mags[mag], (size_t)1);
 }
 
 size_t BinaryMagnitudeSeq::level(int level) const {