To solve the problem that if an execution time decision method is compiled by a conventional method, a method address storing table is created redundantly among different classes.

Method address storage table information, class information, and function reference information are extracted from an intermediate code and analyzed. When other classes do not override one for the execution time decision method against a certain class, a method address storing table of each class is deleted, a method address storing table which can be used for both of the classes in common is generated, method address storing table pointers of both of the classes are updated to the start address value of the generated method address storing table which can be used for the classes of both. Thereby, the method address storing table generated redundantly among the different classes is deleted, and the object code size can be reduced.