Patent · US Expired

Branch selector prediction

US5954816A · kind A · utility

26Cited by
26References
22Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 19, 1997
Grant dateSep 21, 1999
Priority date
Expiry dateNov 19, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F9/3806
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A branch prediction unit includes a branch prediction entry corresponding to a group of contiguous instruction bytes. The branch prediction entry stores branch predictions corresponding to branch instructions within the group of contiguous instruction bytes. Additionally, the branch prediction entry stores a set of branch selectors corresponding to the group of contiguous instruction bytes. The branch selectors identify which branch prediction is to be selected if the corresponding byte (or bytes) is selected by the offset portion of the fetch address. Still further, a predicted branch selector is stored. The predicted branch selector is used to select a branch prediction for forming the fetch address. In parallel, a selected branch selector is selected from the set of branch selectors. The predicted branch selector is verified using the selected branch selector. If the selected branch selector and the predicted branch selector mismatch, the correct branch prediction is generated and the predicted branch selector is updated to indicate the selected branch selector.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.