A method and apparatus for optimizing the compilation of computer program by exposing parallelism are disclosed. The computer program contains steps which involve index expressions. The program also involves function calls. An index path in the program is identified by noting the steps involving index expressions. A non-hierarchical representation of the index path, including operations in the function calls is created and interrogated with questions relating to memory accesses. The results of the interrogation are stored in or back annotated to a question data structure. The method and apparatus preferably involve the use of a signal flow graph which is completed using the information in the question data structure.