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 each row included in the tree divergence table represents a different tree of nodes, and each node represents execution information for at least a portion of a warp of threads, and wherein the first node includes a first warp index array having a plurality of warp indices, each warp index corresponding to at least one warp of threads; setting a first warp index to a value of a first entry included in the first warp index array that corresponds to a first position in the first warp index array; setting a first warp identifier (ID) to a value of a first entry included in a warp mapping table that also corresponds to the first position in the first warp index array; setting a first warp mask to a value of a first entry included in a warp divergence mask table based on the first warp index and the first warp ID; applying the first warp mask to one or more threads included in a first warp of threads specified by the first warp ID determine a first set of active threads; and executing one or more instructions associated with the first node via the first set of active threads.