Flag renaming and flag masks within register alias table
US6047369A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1994 |
| Grant date | Apr 4, 2000 |
| Priority date | — |
| Expiry date | Feb 28, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3885
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A mechanism and method for renaming flags within a register alias table ("RAT") to increase processor parallelism and also providing and using flag masks associated with individual instructions. In order to reduce the amount of data dependencies between instructions that are concurrently processed, the flags used by these instructions are renamed. In general, a RAT unit provides register renaming to provide a larger physical register set than would ordinarily be available within a given macroarchitecture's logical register set (such as the Intel architecture or PowerPC or Alpha designs, for instance) to eliminate false data dependencies between instructions that reduce overall superscalar processing performance for the microprocessor. The renamed flag registers contain several flag bits and various flag bits may be updated or read by different instructions. Also, static and dynamic flag masks are associated with particular instructions and indicate which flags are capable of being updated by a particular instruction and also indicate which flags are actually updated by the instruction. Static flag masks are used in flag renaming and dynamic flag masks are used at retirement. The in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.