Pseudo out-of-order store commit

Abstract

A buffer of a processing system allows younger stores to write to a data cache before an older store completes its write operation to the data cache while maintaining the appearance of committing stores in program order. To maintain the appearance that a blocked store completed its write operation to the data cache, the processing system cancels the blocked store while 'locking' the cache line in the data cache in an exclusive state to which the blocked store is attempting to write. The data cache negatively acknowledges any probes to the cache line until the blocked store has completed the write operation. The buffer thus decouples completing the write operation from global observability of the write operation.