Method and system for safe data dependency collapsing based on control-flow speculation
US6516405B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1999 |
| Grant date | Feb 4, 2003 |
| Priority date | — |
| Expiry date | Dec 30, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3863
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention is directed to an apparatus and method for data collapsing based on control-flow speculation (conditional branch predictions). Because conditional branch outcomes are resolved based on actual data values, the conditional branch prediction provides potentially valuable insight into data values. Upon encountering a branch if equal instruction and this instruction is predicted as taken or a branch if not equal instruction and this instruction is predicted as not taken, this invention assumes that the two operands used to determine the conditional branch are equal. The data predictions are safe because a data misprediction means a conditional branch misprediction which results in a pipeline flush of the instructions following the conditional branch instruction including the data mispredictions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.