Complexity of Scheduling in High Level Synthesis

Abstract

This work examines the complexity of scheduling for high level synthesis. It has been shown that the problem of finding the minimum time schedule for a set of chains of operations of two types using two processors, one of each type, is NP-complete. However, for two chains only, a polynomial time algorithm can been obtained for scheduling with two processors. The problem of scheduling a rooted binary tree of two operation types on two processors, one of each type, has been shown to be NP-complete. It has also been proved that absolute approximations for schedule length minimization or processor minimization are NP-complete. A related resource constrained scheduling problem has also been shown to be NP-hard.