// Set the corresponding bit in var
#define  setbit(var, bit)    ((var) |= (1 << (bit)))

// Clear the corresponding bit in var
#define  clrbit(var, bit)    ((var) &= ~(1 << (bit)))

// Check to see if bit number ‘bit’, in the integer ‘var’ is set
#define  testbit(var, bit)   ((var) & (1 <<(bit)))