On 05/12/16 19:23, Linus Torvalds wrote: > On Mon, Dec 5, 2016 at 9:49 AM, Sebastian Frias <[email protected]> wrote: >> Introduce GENVALUE(msb, lsb, value) macro to ease dealing with >> continuous bitfields, just as BIT(x) does for single bits. > > Oh, and looking at the implementation, this is wrong. You use "lsb" > twice, so it mustn't have side effects. > > That's fine for all expected users (since you'd expect that the only > real use of this is with constant values for msb/lsb),
Yes, that's what I thought. >but please add > actual checking. Sure! Thanks for the advice. > > You can use BUILD_BUG_ON_ZERO(!__builtin_constant_p(x)) or something. > That returns zero, so it's easy to use in expressions. Done. v3 of the patch is submitted. > > Linus >
