A semiconductor chip is described having a functional unit that can execute a first instruction and execute a second instruction. The first instruction is an instruction that multiplies two operands. The second instruction is an instruction that approximates a function according to C0+C1X2+C2X22. The functional unit has a multiplier circuit. The multiplier circuit has: i) a first input to receive bits of a first operand of the first instruction and receive bits of a C1 term of the second instruction; ii) a second input to receive bits of a second operand of the first instruction and receive bits of a X2 term of the second instruction.