Processor with apparatus for tracking prefetch and demand fetch instructions serviced by cache memory

摘要

A processor prefetches instructions in a pipelined manner from a first (L1) cache to a local instruction cache, with an instruction pointer device being utilized to select one of a plurality of incoming addresses for fetching purposes. Instructions returned from the L1 cache are stored in an instruction streaming buffer before they are actually written into the instruction cache. A way multiplexer outputs instructions to dispersal logic in the processor, and is fed by either the local cache or a bypass path that provides the instruction to the way multiplexer from a plurality of bypass sources, which includes the instruction streaming buffer. A request address buffer registers physical and virtual addresses associated with an instruction of a miss request by the processor to the L1 cache. Each entry of the request address buffer has an ID that is sent to the L1 cache with the miss request. This ID is returned to the request address buffer from the L1 cache to read out into the streaming buffer the physical and virtual addresses corresponding to the instruction of the miss request.