摘要 |
Improved performance is obtained in computers of the type capable of parallel instruction execution. The instruction issue process involves checking the reservation flags for the resources required by the instruction. If the resource is available, its reservation flag is set and the instruction is allowed to issue. If the resource is busy, the instruction issue must wait until the resource becomes available. As clock speeds increase, the process of checking for resource conflicts, reserving resources if available, and signalling the status of instruction issue, cannot occur within one clock period. The look-ahead instruction issue control resolves conflicts, reserves resources, and signals the status of instruction issue for a plurality of pre-issue instructions before each of said instructions is in position to issue. The present invention permits instruction issue at every clock period, regardless of the speed of the clock. |