Store load forward predictor training
US6694424B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 2000 |
| Grant date | Feb 17, 2004 |
| Priority date | — |
| Expiry date | Jan 3, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/38585
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A processor employs a store to load forward (STLF) predictor which may indicate, for dispatching loads, a dependency on a store. The dependency is indicated for a store which, during a previous execution, interfered with the execution of the load. Since a dependency is indicated on the store, the load is prevented from scheduling and/or executing prior to the store. The STLF predictor is trained with information for a particular load and store in response to executing the load and store and detecting the interference. Additionally, the STLF predictor may be untrained (e.g. information for a particular load and store may be deleted) if a load is indicated by the STLF predictor as dependent upon a particular store and the dependency does not actually occur. In one implementation, the STLF predictor records at least a portion of the PC of a store which interferes with the load in a first table indexed by the load PC. A second table maintains a corresponding portion of the store PCs of recently dispatched stores, along with tags identifying the recently dispatched stores. In another implementation, the STLF predictor records a difference between the tags assigned to a load and a store …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.