Merge

src/share/vm/opto/graphKit.cpp

@@ -2994,6 +2994,11 @@ Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
   }
 
   Node* cast_obj = NULL;
+  if (tk->klass_is_exact()) {
+    // The following optimization tries to statically cast the speculative type of the object
+    // (for example obtained during profiling) to the type of the superklass and then do a
+    // dynamic check that the type of the object is what we expect. To work correctly
+    // for checkcast and aastore the type of superklass should be exact.
     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
     // We may not have profiling here or it may not help us. If we have
     // a speculative type use it to perform an exact cast.
@@ -3012,6 +3017,7 @@ Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
       }
     }
+  }
 
   if (cast_obj == NULL) {
     // Load the object's klass