Processor with registers storing committed/speculative data and a RAT state history recovery mechanism with retire pointer
US6633970B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1999 |
| Grant date | Oct 14, 2003 |
| Priority date | — |
| Expiry date | Dec 28, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3863
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A mechanism is provided for allowing a processor to recover from a failure of a predicted path of instructions (e.g., from a mispredicted branch or other event). The mechanism includes a plurality of physical registers, each physical register can store either architectural data or speculative data. The apparatus also includes a primary array to store a mapping from logical registers to physical registers, the primary array storing a speculative state of the processor. The apparatus also includes a buffer coupled to the primary array to store information identifying which physical registers store architectural data and which physical registers store speculative data. According to another embodiment, a history buffer is coupled to the secondary array and stores historical physical register to logical register mappings performed for each of a plurality of instructions part of a predicted path. The secondary array is movable to a particular speculative state based on the mappings stored in the history buffer, such as to a location where a path failure may occur. The secondary array can then be copied to the primary array when a failure is detected in a predicted path of instructions ne…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.