def alu_controller(alu_op, funct7,
                   funct3):  # alu_op来自主控制器，funct7和funct3来自指令的特定部位   返回alu_ctrl
    if alu_op == '00':
        opreation = '00000'  # lw.sw.auipc
    elif alu_op == '01':
        if funct3 == '000':
            opreation = '00101'  # beq
        elif funct3 == '001':
            opreation = '00110'  # bne
        elif funct3 == '100':
            opreation = '00111'  # blt
        elif funct3 == '101':
            opreation = '01000'  # bge
        elif funct3 == '110':
            opreation = '01001'  # bltu
        elif funct3 == '111':
            opreation = '01010'  # bgeu
        else:
            opreation = '00000'
    elif alu_op == '10':
        if funct3 == '000':
            if funct7 == '0100000':  # sub
                opreation = '00001'
            else:  # add,addi
                opreation = '00000'
        elif funct3 == '100':
            opreation = '01100'  # xor,xori
        elif funct3 == '110':
            opreation = '00010'  # or,ori
        elif funct3 == '111':
            opreation = '00011'  # and, andi
        elif funct3 == '010':
            opreation = '00100'  # slt,slti
        elif funct3 == '001':
            opreation = '01101'  # sll,slli   未存在
        elif funct3 == '011':
            opreation = '01110'  # sliu,sltiu 未存在
        elif funct3 == '101':
            if funct7 == '0100000':  # sra,srai
                opreation = '01111'
            else:  # srl,srli
                opreation = '10000'
        else:
            opreation = '00000'
    elif alu_op == '11':  # jal
        opreation = '01011'
    else:
        opreation = '00000'
    return opreation