A virtual hint based data cache way prediction scheme, and applications thereof. In an embodiment, a processor retrieves data from a data cache based on a virtual hint value or an alias way prediction value and forwards the data to dependent instructions before a physical address for the data is available. After the physical address is available, the physical address is compared to a physical address tag value for the forwarded data to verify that the forwarded data is the correct data. If the forwarded data is the correct data, a hit signal is generated. If the forwarded data is not the correct data, a miss signal is generated. Any instructions that operate on incorrect data are invalidated and/or replayed.

A data processing apparatus has a cache and a translation look aside buffer (TLB). A way table is provided for identifying which of a plurality of cache ways stores require data. Each way table entry corresponds to one of the TLB entries of the TLB and identifies, for each memory location of the page associated with the corresponding TLB entry, which cache way stores the data associated with that memory location. Also, the cache may be capable of servicing M access requests in the same processing cycle. An arbiter may select pending access requests for servicing by the cache in a way that ensures that the selected pending access requests specify a maximum of N different virtual page addresses, where N<M.

A processing device includes a cache implementing a set of at least three cache slices. Each cache slice is to store a corresponding set of cache lines. The cache further includes cache control logic coupled to the set of at least three cache slices. The cache control logic is to map addresses of an address space to the cache such that each address within the address space maps to a corresponding strict subset of two or more cache slices of the set of cache slices.

A virtual hint based data cache way prediction scheme, and applications thereof. In an embodiment, a processor retrieves data from a data cache based on a virtual hint value or an alias way prediction value and forwards the data to dependent instructions before a physical address for the data is available. After the physical address is available, the physical address is compared to a physical address tag value for the forwarded data to verify that the forwarded data is the correct data. If the forwarded data is the correct data, a hit signal is generated. If the forwarded data is not the correct data, a miss signal is generated. Any instructions that operate on incorrect data are invalidated and/or replayed.

Disclosed is a multi-core processor that includes a processor core, a graphics core, and a cache controller. The cache controller receives a first request from an input-output (I/O) device to lock a first address that corresponds to a way in a first set of ways in a cache. The cache controller sends, to the I/O device, a rejection of the first request when the way in the first set is not lockable for the I/O device. The cache controller receives a second request from the I/O device to lock a second address that corresponds to a way in a second set of ways in the cache. The cache controller locks the way in the second set in response to the second request.

Optimizing cache energy consumption in processor-based devices is disclosed herein. In some aspects, a processor-based device comprises a way lookup table (WLUT) circuit that is configured to receive an effective address (EA) for a memory access request. The WLUT circuit determines that a tag portion of the EA corresponds to a tag of a WLUT entry among a plurality of WLUT entries. In response, the WLUT circuit transmits a predicted way indicator of the WLUT entry to a cache controller. The cache controller accesses, in a set among a plurality of sets of a cache memory device corresponding to a set portion of the EA, only a predicted tag way among a plurality of tag ways of the cache memory device indicated by the predicted way indicator and only a predicted data way among a plurality of data ways of the cache memory device indicated by the predicted way indicator.

A cache subsystem is disclosed. The cache subsystem includes a cache configured to store information in cache lines arranged in a plurality of ways. A requestor circuit generates a request to access a particular cache line in the cache. A prediction circuit is configured to generate a prediction of which of the ways includes the particular cache line. A comparison circuit verifies the prediction by comparing a particular address tag associated with the particular cache line to a cache tag corresponding to a predicted one of the ways. Responsive to determining that the prediction was correct, a confirmation indication is stored indicating the correct prediction. For a subsequent request for the particular cache line, the cache is configured to forego a verification of the prediction that the particular cache line is included in the one of the ways based on the confirmation indication.