--- a/src/hotspot/cpu/aarch64/register_aarch64.hpp	Thu Oct 17 20:27:44 2019 +0100
+++ b/src/hotspot/cpu/aarch64/register_aarch64.hpp	Thu Oct 17 20:53:35 2019 +0100
@@ -136,7 +136,7 @@
   VMReg as_VMReg();
 
   // derived registers, offsets, and addresses
-  FloatRegister successor() const                          { return as_FloatRegister(encoding() + 1); }
+  FloatRegister successor() const                          { return as_FloatRegister((encoding() + 1) % 32); }
 
   // accessors
   int   encoding() const                          { assert(is_valid(), "invalid register"); return (intptr_t)this; }
@@ -230,6 +230,11 @@
     return *this;
   }
 
+  RegSet &operator-=(const RegSet aSet) {
+    *this = *this - aSet;
+    return *this;
+  }
+
   static RegSet of(Register r1) {
     return RegSet(r1);
   }