Electrical computers: arithmetic processing and calculating – Electrical digital calculating computer – Particular function performed
Reexamination Certificate
2006-07-18
2006-07-18
Ngo, Chuong D. (Department: 2193)
Electrical computers: arithmetic processing and calculating
Electrical digital calculating computer
Particular function performed
Reexamination Certificate
active
07080112
ABSTRACT:
A method and apparatus allows the quick computation of an estimate of the reciprocal of a floating point number in IEEE format. A table with 2kentries allows the computation of an estimate with 2×k+3 good bits. x is a floating point number in IEEE format for which a reciprocal approximation is to be computed. {circumflex over (x)} be a floating point number in IEEE format derived from x by leaving the sign bit unchanged, complementing the exponent bits, leaving the first k fraction bits unchanged, and complementing the remaining fraction bits. t is another floating point number in IEEE format found by using the first k bits of the fraction of x as an index into a table with 2kentries. The product {circumflex over (x)}×t computed with IEEE floating point arithmetic is an estimate of the reciprocal of x with 2×k+3 good bits (i.e., relative error less than 2−2×k+3).
REFERENCES:
patent: 5153851 (1992-10-01), Kanazawa et al.
patent: 5563818 (1996-10-01), Agarwal et al.
patent: 5768171 (1998-06-01), Chow
patent: 6163791 (2000-12-01), Schmookler et al.
patent: 6240433 (2001-05-01), Schmookler et al.
patent: 6260054 (2001-07-01), Rosman et al.
patent: 6769006 (2004-07-01), Krouglov et al.
International Business Machines - Corporation
Kaufman Stephen C.
Ngo Chuong D.
Whitham Curtis Christofferson & Cook PC
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