Speculative pre-fetching additional line on cache miss if no request pending in out-of-order processor
US6643766B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 2000 |
| Grant date | Nov 4, 2003 |
| Priority date | — |
| Expiry date | May 4, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0862
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Speculative pre-fetching and pre-flushing of additional cache lines minimize cache miss latency and coherency check latency of an out of order instruction execution processor. A pre-fetch/pre-flush slot (DPRESLOT) is provided in a memory queue (MQUEUE) of the out-of-order execution processor. The DPRESLOT monitors the transactions between a system interface, e.g., the system bus, and an address reorder buffer slot (ARBSLOT) and/or between the system interface and a cache coherency check slot (CCCSLOT). When a cache miss is detected, the DPRESLOT causes one or more cache lines in addition to the data line, which caused the current cache miss, to be pre-fetched from the memory hierarchy into the cache memory (DCACHE) in anticipation that the additional data would be required in the near future. When a cache write back is detected as a result of a cache coherency check, the DPRESLOT causes one or more cache lines, in addition to the data line currently being written back, to be pre-flushed out to the memory hierarchy from the respective cache memory (DCACHE) of the processor that owns the line, in anticipation that the additional data would be required by the requesting processor in t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.