A method and apparatus for improving the process of determining whether two computer system memory references are exactly dependent. While loop unrolling creates a large number of memory reference pairs which must be analyzed during the data dependence analysis phase of compiler optimization, this invention reduces the computer resources required for this analysis. When two memory references are exactly dependent, the present invention quickly determines the distance between them by an elegant method which uses easily accessible values. Therefore, if two memory references are exactly dependent, and if the distance is an integral greater than zero then the compiler optimizer may re-use the same data in computer memory and thus reduce the need to execute computer register instructions. Alternately, if the two memory references are independent they become candidates for pipeline scheduling. This further reduces the use of computer resources.