On Tue, 30 Jan 2007, Jan Engelhardt wrote: > > On Jan 30 2007 09:45, Robert P. J. Day wrote:
> >seriously, though, there is the potential of breaking something with > >this change since you can see how there is some inconsistency in how > >it's done *now* just for powerpc which, in some places, defines its > >own versions of this: > > > >./arch/ppc/mm/pgtable.c: > > #define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) > >./arch/ppc/syslib/ppc85xx_rio.c: > > #define is_power_of_2(x) (((x) & ((x) - 1)) == 0) > >./arch/powerpc/mm/pgtable_32.c: > > #define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) > > > >note how the first and third macros *won't* consider zero a power of > >two, while the second one *will*. hence the need for a single > >standard for all of this, just to play it safe. > > Hmpf. Perhaps a second macro "is_intdivisible_by_power_of_2" or so could > catch the "am I zero or 2^n" question. no. if that's really what the programmer wants, they can code it that way explicitly. let's not make this overly obscure. rday - 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/
