Confirming store-to-load forwards

摘要

A processor includes a store queue that stores information representing store instructions. In response to retirement of a store instruction, the processor invalidates the corresponding entry in the store queue, thereby indicating that the entry is available to store a subsequent store instruction. The store address is not removed from the queue until the subsequent store instruction is stored. Accordingly, the store address is available for comparison to a dependent load address.

主权项

1. A method to determine at a processor if a store-to-load forward operation has provided correct data to a load instruction, the method comprising:
storing first information representing a first store instruction at a queue; performing the store-to-load forward operation by forwarding data of the first store instruction to the load instruction; retiring the first store instruction after performing the store-to-load forward operation; continuing to maintain the first information at the queue after performing the store-to-load forward information and the first store instruction has retired; and confirming, after the first store instruction has retired, the store-to-load forward operation based on the first information stored at the queue, wherein confirming comprises determining whether correct data was provided to the load instruction by the store-to-load forward operation.