SPECIALIZED PROCESSING BLOCK FOR IMPLEMENTING FLOATING-POINT MULTIPLIER WITH SUBNORMAL OPERATION SUPPORT

The functions available in a specialized processing block of a programmable device include floating-point operations, including support within the specialized processing block for subnormal operations. This is accomplished, in part, by borrowing an adder in the specialized processing block and using the adder to operate on output of a multiplier or other operator to compete a subnormal operation. Although the adder becomes unavailable to serve as an adder, the need to complete the operation in slower, more valuable general purpose logic is avoided. The adder and the other operator need not necessarily be located together in a specialized processing block.