Method and apparatus for correctly rounding results of division

Details Method and apparatus for correctly rounding results of division Method and apparatus for correctly rounding results of division

1994-07-01

1997-09-23

Mai, Tan V.

Boots, shoes, and leggings

G06F 738

Patent

active

056711700

ABSTRACT:
A floating point arithmetic unit for correctly rounding a quotient or a square root of high precision numbers to the floating point number closest to the exact result is disclosed. The invention is generally applicable to round results to a precision greater than that provided by the floating point hardware. Prior to rounding, the hardware within the floating point unit produces a high precision mantissa with all but the last few digits correct. The rounding technique according to the invention is then used to produce a correctly rounded result using an enhanced Tuckerman test. Unlike a conventional Tuckerman test, the enhanced Tuckerman test determines the last few ULPs for both square root and division while checking for early termination. The advantage of checking for early termination is that the computation time needed to make the rounding decision can be significantly reduced.

REFERENCES:
patent: 4562553 (1985-12-01), Mattedi et al.
patent: 4999801 (1991-03-01), Katsuno
patent: 4999802 (1991-03-01), Cocanougher et al.
patent: 5042001 (1991-08-01), Brightman et al.
patent: 5157624 (1992-10-01), Hesson
patent: 5220524 (1993-06-01), Hesson
P.W. Markstein, "Computation of Elementary Functions on the IBM RISC System/6000 Procressor", IBM Journal of Research and Development, vol. 34, No. 1, Jan. 1990.

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