Messages in this thread | | | From | Jani Nikula <> | Subject | Re: [PATCH v2 18/20] linux/power_of_2.h: Add __IS_POWER_OF_2(n) and __IS_POWER_OF_2_OR_0(n) macros | Date | Mon, 22 Nov 2021 10:55:28 +0200 |
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On Sun, 21 Nov 2021, Arnd Bergmann <arnd@arndb.de> wrote: > On Sat, Nov 20, 2021 at 2:01 PM Alejandro Colomar > <alx.manpages@gmail.com> wrote: >> + >> +#define __IS_POWER_OF_2_OR_0(n) (((n) & ((n) - 1)) == 0) >> +#define __IS_POWER_OF_2(n) (__IS_POWER_OF_2_OR_0(n) && ((n) != 0)) >> + > > There is already is_power_of_2() in include/linux/log2.h, which would > be preferred > in most cases. If you need a macro version, put it in the same file > and explain why it's > needed.
Also, the macro argument n is evaluated 2-3 times. Please use checkpatch.pl --strict argument on the patches, and it'll give you hints about this stuff too.
BR, Jani.
-- Jani Nikula, Intel Open Source Graphics Center
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