1. A computer-implemented method for determining a set of active threads to execute a set of instructions, the method comprising: accessing a first node included in a tree divergence table that is configured for managing thread execution within a processing entity, wherein the first node is associated with a first instruction and a first warp index array; setting a first warp index to a value of an entry included in the first warp index array that corresponds with a first position; setting a first warp id to a value of an entry included in a warp mapping table that corresponds to the first position; setting a first warp mask to a value of an entry included in a warp divergence mask table based on the first warp index and the first warp id; and applying the first warp mask to one or more threads included in a first warp of threads specified by the first warp id to determine a first set of active threads.