Patent ID: 9696964
Date: 2017-07-04
CPC Classifications: G06F

Claim:
1. Apparatus for performing an arithmetic operation A+(B*C), where A, B and C are floating point numbers each having an exponent value within an exponent value range and a mantissa value, said apparatus comprising: multiplier circuitry configured to multiply B and C to generate a product having a product mantissa value and a product exponent value; and adder circuitry configured to add A and said product to generate a result value; wherein said multiplier circuitry is configured to generate said product exponent value passed to said adder circuitry within an extended exponent value range that extends to lower values than said exponent value range, wherein said multiplier circuitry is configured, when said product exponent has a value lower than said exponent value range, to generate an out-of-range exponent flag signal sent to said adder circuitry; and said adder circuitry is configured to receive said product exponent value within said extended exponent value range, to determine how to interpret said product exponent value in dependence on whether said out-of-range exponent flag signal has been generated by said multiplier circuitry, and to generate said result value with a result exponent within said exponent value range.