Patent ID: 8392490

Claim:
A method of identifying decimal floating point addition operations that guarantee operand alignment and do not require alignment, normalization or rounding, the method comprising: receiving an instruction at a processor, from an instruction unit, to perform an addition of a first operand and a second operand; and prior to performance of the addition, performing by the processor: extracting a first exponent (EXP) and a first most significant digit (MSD) from the first operand; extracting a second EXP and a second MSD from the second operand; and determining whether the first operand and the second operand are aligned, based on the first EXP, the first MSD, the second EXP and the second MSD, wherein determining includes calculating a sum of the first MSD and the second MSD and calculating a difference between the first EXP and the second EXP, and wherein no additional alignment, normalization or rounding is necessary if the sum is less than nine and if the difference is equal to zero.