Multiply-add method and multiply-add apparatus

The invention disclose a multiply-add method and multiply-add apparatus, the method comprises the following steps: (1) a multiplier generates a plurality of control signals through a Bush coding logical unit, a multiplicand serves as the input of a partial product generating logical unit, and a partial product is generated; (2) an addend obtains a lower-order intercepting part, an intermediate part and a higher-order intercepting part through an addend partitioning logical unit; the lower-order intercepting part, the intermediate part and the partial product serve as the input of an improved Wallace tree unit, the obtained result serves as the input of an adder, and a lower-order result and a control signal are generated; 3 the higher-order intercepting part obtains a higher-order result through a higher-order forecasting logical unit; and (4) the lower-order result and the higher-order result obtains a final result through a matching logical unit. The multiply-add apparatus comprise the Bush coding logical unit, the partial product generating logical unit, the addend partitioning logical unit, the adder, the higher-order forecasting logical unit, the improved Wallace tree unit and the matching logical unit. The invention has the advantages of simple and compact structure, low cost, quick arithmetic speed, stabilization, reliability, and the like.