These routines work fine with IAR and Keil ,but I've no idea how SDCC will mangle them..

U8 bit_test(U8 cbyte,U8 cbit) {
    return(((cbyte &(1 << cbit))!=0));}

U8 bit_set(U8 cbyte,U8 cbit) {
    cbyte |=(1 << cbit);
    return(cbyte);}

U8 bit_clear(U8 cbyte,U8 cbit) {
    cbyte &=~(1 << cbit);
    return(cbyte);}