Abstract: An embodiment of a method and a related apparatus for digital computation of a floating point complex multiply-add is provided. The method includes receiving an input addend, a first product, and a second product. The input addend, the first product and the second product each respectively has a mantissa and an exponent. The method includes shifting the mantissas of the two with smaller exponents of the input addend, the first product, and the second product to align together with the mantissa of the one with largest exponent of the input addend, the first product and the second product, and adding the aligned input addend, the aligned first product and the aligned second product.

Abstract: An embodiment of an apparatus performs a floating-point multiply-add process on a first multiplicand, a second multiplicand, and an addend. A leading 0 bit is added to a mantissa of the first multiplicand to form an expanded first mantissa, and a partial-product multiplication is performed on the expanded first mantissa and a mantissa of the second multiplicand to produce partial-product sum and a partial-product carry mantissas. Leading bits of the partial-product sum and carry mantissas are changed to 0 bits if they are both 1 bits, and the partial-product sum and the partial-product carry are shifted right according to an exponent difference of a product of the first multiplicand and the second multiplicand. Otherwise both the partial-product sum and carry mantissas are arithmetically shifted right according to the exponent difference. The first and second multiplicands and the addend can be complex numbers.

Abstract: An embodiment of a method and a related apparatus for digital computation of a floating point complex multiply-add is provided. The method includes receiving an input addend, a first product, and a second product. The input addend, the first product and the second product each respectively has a mantissa and an exponent. The method includes shifting the mantissas of the two with smaller exponents of the input addend, the first product, and the second product to align together with the mantissa of the one with largest exponent of the input addend, the first product and the second product, and adding the aligned input addend, the aligned first product and the aligned second product.

Abstract: An embodiment of an apparatus performs a floating-point multiply-add process on a first multiplicand, a second multiplicand, and an addend. A leading 0 bit is added to a mantissa of the first multiplicand to form an expanded first mantissa, and a partial-product multiplication is performed on the expanded first mantissa and a mantissa of the second multiplicand to produce partial-product sum and a partial-product carry mantissas. Leading bits of the partial-product sum and carry mantissas are changed to 0 bits if they are both 1 bits, and the partial-product sum and the partial-product carry are shifted right according to an exponent difference of a product of the first multiplicand and the second multiplicand. Otherwise both the partial-product sum and carry mantissas are arithmetically shifted right according to the exponent difference. The first and second multiplicands and the addend can be complex numbers.