Method for repairing a speculative global history record
US7975133B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 2011 |
| Grant date | Jul 5, 2011 |
| Priority date | — |
| Expiry date | Jan 29, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3863
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system and method are provided for updating a speculative global history prediction record in a microprocessor system using pipelined instruction processing. The method accepts microprocessor instructions with consecutive operations, including a conditional branch operation with an associated first branch address. A speculative global history record (SGHR) of conditional branch resolutions and predictions is accessed and hashed with the first branch address, creating a first hash result. The first hash result is used to index a branch history table (BHT) of previous first branch resolutions. As a result, a first branch prediction is made, and the SGHR is updated with the first branch prediction. A non-speculative global history record (NSGHR) of branch resolutions is updated with the resolution of the first branch operation, and if the first branch prediction is incorrect, the SGHR is corrected using the NSGHR.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.