--- old/src/hotspot/share/utilities/ticks.hpp	2018-04-16 13:05:22.230615521 +0200
+++ new/src/hotspot/share/utilities/ticks.hpp	2018-04-16 13:05:21.963607334 +0200
@@ -47,6 +47,11 @@
     return *this;
   }
 
+  Tickspan& operator-=(const Tickspan& rhs) {
+    _span_ticks -= rhs._span_ticks;
+    return *this;
+  }
+
   jlong value() const {
     return _span_ticks;
   }