Problem about location of local variable in data memory

I have problem about location of local variable in data memory. In my code

void WRITE_RTC(uchar Dat,uchar Addr)
{
xxx=(RTC_ADDR|WRITE);
Start();
Out_Byte(xxx);
Out_Byte(Addr);
Out_Byte(Dat);
Stop();
}

but in M51 file it show

TYPE BASE LENGTH RELOCATION SEGMENT NAME
DATA 0074H 0002H UNIT ?DT?_WRITE_RTC?I2C_DEVICE_FUNCTION3

in function I have only local variable uchar Dat,uchar Addr why keil fix address for them