CODE OPTIMIZATION OF STRAIGHT-LINE PROGRAMS FOR A DATA-FLOW MACHINE.

The author discusses code optimization and presents an algorithm for conversion from straight-line programs for a data-flow machine consisting only of artihmetic instructions to an optimum code (i. e. , to an object program with minimum execution time). It is first assumed that the execution time of each operation depends on the value of the input data. Based on that assumption, a control unit for extracting instructions is proposed which dynamically determines the execution order of instructions to which combinational law is applicable. It is then examined whether or not the execution time can be decreased by eliminating common factors by distributive law. An algorithm is presented to determine the optimum code when algebraic law is applied. It is also shown that the computation time is O(n**2).