BIT_MASK
#define BIT_MASK(nr) (1UL << ((nr) & (BITS_PER_LONG - 1)))
#define BIT_MASK(nr) (1UL << ((nr) & (BITS_PER_LONG - 1)))
#define BIT_MASK(nr) (1UL << ((nr) & (BITS_PER_LONG - 1)))
#define BIT_MASK 0x1f /* Defines for third byte of header. */
#define BIT_MASK 0x1f /* Defines for third byte of header. */