Decoupled forwarding reorder buffer configured to allocate storage in chunks for instructions having unresolved dependencies

摘要

A reorder buffer is provided which decouples allocation of storage space within the buffer for storing instructions from forwarding of the corresponding operands. When instructions are presented to the reorder buffer for storage and dependency checking, the reorder buffer allocates storage for the instructions and corresponding instruction results. If an unresolved dependency is detected, the instructions remain stored in the reorder buffer but operand forwarding is delayed until the unresolved dependency becomes resolved. Advantageously, the previously included extra storage and multiplexing prior to dependency checking may be eliminated. Additional clock cycle time may be available for performing dependency checking. Additionally, area formerly occupied by the extra storage is freed for other purposes.