Method and apparatus for efficiently performing a square root operation
US7139786B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 12, 2003 |
| Grant date | Nov 21, 2006 |
| Priority date | — |
| Expiry date | Mar 9, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2207/5528
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
One embodiment of the present invention provides a system that performs a carry-save square root operation that calculates an approximation of a square root, Q, of a radicand, R. The system calculates Q by iteratively selecting an operation to perform based on higher-order bits of a remainder, r, and then performs the operation. This operation can include subtracting two times a square root calculated thus far, q, and a coefficient, c, from r, and adding c to q. During this operation, the system maintains r in carry-save form, which eliminates the need for carry propagation while updating r, thereby speeding up the square root operation. Furthermore, the selection logic, which decides what operation to perform next, is simpler than previous square-root implementations, thereby providing a further speedup.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.