PROCESSING UNIT

A processing unit computes a trigonometric function, for decrease the number of instructions and improve throughput. In a floating point multiply-add circuit, an OR circuit, a selector and an EOR circuit are disposed, and an expansion point and expansion function of the Taylor series expansion of the trigonometric function are computed using a first trigonometric function operation auxiliary instruction for defining the operation of rd=(rs1*rs1)|(rs2 [0]<<63) and a second trigonometric function operation auxiliary instruction for defining the operation of rd=((rs2 [0])? 1.0: rs1)^(rs2 [1]<<63), or a third trigonometric function operation auxiliary instruction for defining the operation of rd=(rs1*rs1)|((˜rs2 [0]<<63) and a fourth trigonometric function operation auxiliary instruction for defining the operation of rd=((rs2 [0])? rs1: 1.0)^((rs2 [1]^rs2 [0])<<63)).