--- old/src/share/vm/c1/c1_Canonicalizer.cpp	2016-02-25 22:50:45.130287415 +0300
+++ new/src/share/vm/c1/c1_Canonicalizer.cpp	2016-02-25 22:50:45.086287632 +0300
@@ -487,6 +487,17 @@
     }
     break;
   }
+  case vmIntrinsics::_isPrimitive        : {
+    assert(x->number_of_arguments() == 1, "wrong type");
+
+    // Class.isPrimitive is known on constant classes:
+    InstanceConstant* c = x->argument_at(0)->type()->as_InstanceConstant();
+    if (c != NULL && !c->value()->is_null_object()) {
+      ciType* t = c->value()->as_instance()->java_mirror_type();
+      set_constant(t->is_klass() ? 0 : 1);
+    }
+    break;
+  }
   }
 }