US Patent 9804666 Warp clustering

Units of shader work, such as warps or wavefronts, are grouped into clusters. An individual vector register file of a processor is operated as segments, where a segment may be independently operated in an active mode or a reduced power data retention mode. The scheduling of the clusters is selected so that a cluster is allocated a segment of the vector register file. Additional sequencing may be performed for a cluster to reach a synchronization point. Individual segments are placed into the reduced power data retention mode during a latency period when the cluster is waiting for execution of a request, such as a sample request.