8058825: EA: ConnectionGraph::split_unique_types does incorrect scalar replacement

Reviewed-by: kvn

src/share/vm/opto/escape.cpp

@@ -2839,6 +2839,13 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist)
           continue;
         }
       }
+
+      const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
+      if (t == NULL)
+        continue;  // not a TypeOopPtr
+      if (!t->klass_is_exact())
+        continue; // not an unique type
+
       if (alloc->is_Allocate()) {
         // Set the scalar_replaceable flag for allocation
         // so it could be eliminated.
@@ -2857,10 +2864,7 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist)
       //   - not determined to be ineligible by escape analysis
       set_map(alloc, n);
       set_map(n, alloc);
-      const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
-      if (t == NULL)
-        continue;  // not a TypeOopPtr
-      const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
+      const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
       igvn->hash_delete(n);
       igvn->set_type(n,  tinst);
       n->raise_bottom_type(tinst);