MULLW reg1 reg2 ri -> usage (reg2 : regRI ri, [reg1])
DIVW reg1 reg2 reg3-> usage ([reg2,reg3], [reg1])
DIVWU reg1 reg2 reg3-> usage ([reg2,reg3], [reg1])
MULLW reg1 reg2 ri -> usage (reg2 : regRI ri, [reg1])
DIVW reg1 reg2 reg3-> usage ([reg2,reg3], [reg1])
DIVWU reg1 reg2 reg3-> usage ([reg2,reg3], [reg1])