Method and apparatus for coordinating the use of physical registers in a microprocessor
US5740414A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1995 |
| Grant date | Apr 14, 1998 |
| Priority date | — |
| Expiry date | Aug 17, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3863
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a microprocessor, an apparatus is included for coordinating the use of physical registers in the microprocessor. Upon receiving an instruction, the coordination apparatus extracts source and destination logical registers from the instruction. For the destination logical register, the apparatus assigns a physical address to correspond to the logical register. In so doing, the apparatus stores the former relationship between the logical register and another physical register. Storing this former relationship allows the apparatus to backstep to a particular instruction when an execution exception is encountered. Also, the apparatus checks the instruction to determine whether it is a speculative branch instruction. If so, then the apparatus creates a checkpoint by storing selected state information. This checkpoint provides a reference point to which the processor may later backup if it is determined that a speculated branch was incorrectly predicted. Overall, the apparatus coordinates the use of physical registers in the processor in such a way that: (1) logical/physical register relationships are easily changeable; and (2) backup and backstep procedures are accommodated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.