Two-level branch prediction apparatus
US7831817B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 15, 2003 |
| Grant date | Nov 9, 2010 |
| Priority date | — |
| Expiry date | Sep 24, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3848
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A two-level branch prediction apparatus includes branch bias logic for predicting whether a branch instruction will result in a branch being taken. Upon receipt of a first address portion of a branch instruction's address, a first store outputs a corresponding first branch bias value. A history store stores history data identifying an actual branch outcome for preceding branch instructions. A second store stores multiple entries, each entry including a replacement branch bias value and a TAG value. An index derived from the history data causes the second store to output a corresponding entry. The first branch bias value is selected unless the TAG value corresponds to a comparison TAG value derived from a second address portion of the branch instruction's address, in which event, the replacement branch bias value is selected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.