diff -r 2b0b7f222800 -r a81c930a8838 src/hotspot/share/opto/mathexactnode.hpp
--- a/src/hotspot/share/opto/mathexactnode.hpp	Tue Jan 23 14:27:10 2018 -0500
+++ b/src/hotspot/share/opto/mathexactnode.hpp	Thu Jan 18 19:21:11 2018 +0100
@@ -129,8 +129,10 @@
   OverflowMulLNode(Node* in1, Node* in2) : OverflowLNode(in1, in2) {}
   virtual int Opcode() const;
 
-  virtual bool will_overflow(jlong v1, jlong v2) const;
+  virtual bool will_overflow(jlong v1, jlong v2) const { return is_overflow(v1, v2); }
   virtual bool can_overflow(const Type* t1, const Type* t2) const;
+
+  static bool is_overflow(jlong v1, jlong v2);
 };
 
 #endif