Method and apparatus for exponent adder.

摘要

An apparatus and method for determining the difference between two exponents of two floating point numbers is disclosed. The exponent of each number is split into two portions. A high portion (52,56) contains the most significant bits and a low portion (54,58) contains the least significant bits. The number of bits in the low portion is related to the number of bits in the fraction portion (16b,18b) of each floating point number. To determine differences that require a shift in one of the fractions, one of the differences between the low portions of the exponents is selected (74) based upon which of several conditions are found with respect to the difference between the high portions (66). Advantageously, a set of adders (60,62) which are only as wide as the number of bits in the low portion of each exponent are used. <IMAGE>