Retaining flag value associated with dead result data in freed rename physical register with an indicator to select set-aside register instead for renaming
US7043626B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 2003 |
| Grant date | May 9, 2006 |
| Priority date | — |
| Expiry date | Dec 1, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/384
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for retaining flag values when an associated data value dies. A first storage circuit includes a free list for storing physical register names (PRNs) and indications indicative of whether a physical register associated with a PRN was assigned to store a logical register result and flag results of a first instruction and a logical register result and a subsequent instruction which overwrites the logical register result but not the flags. A second storage circuit stores PRNs separate from the free list. The first and second storage circuits output first and second PRNs to a selection circuit. If the first indication (associated with the first PRN) is in a first state, the selection circuit may provide the first PRN to a mapper for assignment to a logical register. If the first indication is in a second state, the second PRN may be provided to the mapper.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.