The canonical functional design based on the domination-relationship among data

Abstract

We study the problem of creating a functional design from a dataflow diagram D. We use the domination-relationship on data-items in D to obtain a canonical function calling-scheme S(D) which is optimal in that it uses the minimum number of global variables for the interface among functions, while keeping the function parameters to a minimum. The difficulty of determining a function calling-scheme that is both valid and optimal is because the number of valid calling-schemes is exponentially large in the size of D. We also use S(D) to obtain a decomposition of D into larger single-output function-blocks. In previous work we give an algorithm to generate the basic pseudocode for each function, including its interface, for the calling-scheme S(D).