On Tue, Nov 04 2014, Maxime COQUELIN <[email protected]> wrote: > -#define GENMASK(h, l) (((U32_C(1) << ((h) - (l) + 1)) - 1) << > (l)) > -#define GENMASK_ULL(h, l) (((U64_C(1) << ((h) - (l) + 1)) - 1) << (l)) > +#define GENMASK(h, l) \ > + ((~0UL >> (BITS_PER_LONG - ((h) - (l) + 1))) << (l)) > + > +#define GENMASK_ULL(h, l) \ > + ((~0ULL >> (BITS_PER_LONG_LONG - ((h) - (l) + 1))) << (l))
Slightly bikeshedding here, but may I suggest spelling it (((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h)))) ? This will ensure the arguments are expanded once each, and will, IMHO, DTRT if/when l > h (namely, yield 0). Rasmus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
