The list scheduling algorithm is a popular scheduling engine used in most, if not all, industrial instruction schedulers. However this technique has several drawbacks, especially in the context of modulo scheduling. One such problem is the need to restart scheduling from scratch whenever scheduling fails at the current value of the initiation interval. Another problem of list scheduling is that the order in which the instructions are selected for scheduling is constrained to be a topological sort of the scheduling graph, minus the loop-carried dependencies.