diff -r e92153ed8bdc -r 29b0d0b61615 src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp	Mon Nov 25 12:30:24 2019 +0100
+++ b/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp	Mon Nov 25 12:31:39 2019 +0100
@@ -620,7 +620,7 @@
 }
 
 void ShenandoahHeap::increase_used(size_t bytes) {
-  Atomic::add(bytes, &_used);
+  Atomic::add(&_used, bytes);
 }
 
 void ShenandoahHeap::set_used(size_t bytes) {
@@ -633,7 +633,7 @@
 }
 
 void ShenandoahHeap::increase_allocated(size_t bytes) {
-  Atomic::add(bytes, &_bytes_allocated_since_gc_start);
+  Atomic::add(&_bytes_allocated_since_gc_start, bytes);
 }
 
 void ShenandoahHeap::notify_mutator_alloc_words(size_t words, bool waste) {
@@ -1350,7 +1350,7 @@
 
     size_t max = _heap->num_regions();
     while (_index < max) {
-      size_t cur = Atomic::add(stride, &_index) - stride;
+      size_t cur = Atomic::add(&_index, stride) - stride;
       size_t start = cur;
       size_t end = MIN2(cur + stride, max);
       if (start >= max) break;