Messages in this thread | | | Date | Wed, 06 Jan 2010 16:15:04 -0500 | From | David Dillow <> | Subject | Re: [PATCH] log2.h: Macro-ize is_power_of_2() for use in BUILD_BUG_ON |
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On Wed, 2010-01-06 at 12:44 -0800, Roland Dreier wrote: > > Perhaps we can avoid worrying about that via > > > #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ > > BUILD_BUG_ON((n != 0 && ((n & (n - 1)) == 0))) > > Having something so specific to this particular case makes me feel like > maybe it's just not worth it. At least in the case I'm looking at, we > could just have: > > /* > * The code relies on FOO being a power of 2. If you break this, > * you're dumb. > */ > #define FOO_SHIFT 6 > #define FOO (1 << FOO_SHIFT) > > Your thoughts?
I'm fine with that, but now I'll probably be the dumb one to break it some day in the future.
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