Fast lane prefetching
US6681295B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2000 |
| Grant date | Jan 20, 2004 |
| Priority date | — |
| Expiry date | Mar 19, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/6028
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer system has a set-associative, multi-way cache system, in which at least one way is designated as a fast lane, and remaining way(s) are designated slow lanes. Any data that needs to be loaded into cache, but is not likely to be needed again in the future, preferably is loaded into the fast lane. Data loaded into the fast lane is earmarked for immediate replacement. Data loaded into the slow lanes preferably is data that may not needed again in the near future. Slow data is kept in cache to permit it to be reused if necessary. The high-performance mechanism of data access in a modem microprocessor is with a prefetch; data is moved, with a special prefetch instruction, into cache prior to its intended use. The prefetch instruction requires less machine resources, than carrying out the same intent with an ordinary load instruction. So, the slow-lane, fast-lane decision is accomplished by having a multiplicity of prefetch instructions. By loading “not likely to be needed again” data into the fast lane, and designating such data for immediate replacement, data in other cache blocks, in the other ways, may not be evicted, and overall system performance is increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.