Mechanism and apparatus allowing an N-way set associative cache, implementing a hybrid pseudo-LRU replacement algorithm, to have N L1 miss fetch requests simultaneously inflight regardless of their congruence class

摘要

A method, system, and computer program product for supporting multiple fetch requests to the same congruence class in an n-way set associative cache. Responsive to receiving an incoming fetch instruction at a load/store unit, outstanding valid fetch entries in the n-way set associative cache that have the same cache congruence class as the incoming fetch instruction are identified. SetIDs in used by these identified outstanding valid fetch entries are determined. A resulting setID is assigned to the incoming fetch instruction based on the identified setIDs, wherein the resulting setID assigned is a setID not currently in use by the outstanding valid fetch entries. The resulting setID for the incoming fetch instruction is written in a corresponding entry in the n-way set associative cache.