The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 25, 2001
Filed:
Aug. 11, 1998
David Resnick, Eau Claire, WI (US);
William T. Moore, Elk Mound, WI (US);
Cray, Inc., Eagan, MN (US);
Abstract
An apparatus and a method for extended-precision vector arithmetic capable of extremely long precision (i.e., precision to as many bits as a user desires or is limited to due to memory, disk-storage, or other resource constraints). Vector carry-out bits can be used as vector carry-in bits for successive operations. In performing add or subtract operations on integers that are longer than the word size of the computer, the operands a broken into word-sized parts which are used as operands. A vector of long-integer numbers is thus broken into a series of sub-vectors, each having word-sized elements. Vector add or subtract operations are performed successively on the sub-vectors, starting with the lowest-order sub-vectors. Carry-out (or borrow-out) bits from a first vector operation are used as carry-in (or borrow-in) bits for a successive vector operation. In one embodiment, instructions are added to the instruction set of a vector processor to assist in propagating carry (or borrow) bits between components of long operands, and to assist users in accessing and controlling the carry (or borrow) bits.