MECHANISM FOR FAST DETECTION OF OVERSHIFT IN A FLOATING POINT UNIT

摘要

A floating point unit includes a floating point adder to perform a floating point addition operation between first and second floating point numbers each having an exponent and a mantissa. The floating point unit also includes an alignment shifter that may calculate a shift value corresponding to a number of bit positions to shift the second mantissa such that the second exponent value is the same as the first exponent value. The alignment shifter may detect an overshift condition, in which the shift value is greater than or equal to a selected overshift threshold value. The selected overshift threshold value comprises a base 2 number in a range of overshift values including a minimum overshift threshold value and a maximum overshift threshold value, and which has a largest number of a consecutive of bits that are zero beginning at a least significant bit.