Scheduling arithmetic and load operations in parallel with no spilling

A machine model in which load operations can be performed in parallel with arithmetic operations by two separate functional units is considered. For this model, the evaluation of a set of expression trees is discussed. A dynamic programming algorithm for producing an approximate solution is described and analyzed. For binary trees its worse-case cost is at most min (1.091, 1 + (2 log n)/n) times the optimal cost.