Re: [PATCH] Add "is_power_of_2" checking to log2.h.

[Nick Piggin]

Robert P. J. Day wrote:
>   Add the inline function "is_power_of_2()" to log2.h, where the value
> zero is *not* considered to be a power of two.

> Signed-off-by: Robert P. J. Day <rpjday@xxxxxxxxxxxxxx>
>
>  /*
> + *  Determine whether some value is a power of two, where zero is
> + * *not* considered a power of two.
> + */

Why the qualifier? Zero *is* not a power of 2, is it?

> +
> +static inline __attribute__((const))
> +bool is_power_of_2(unsigned long n)
> +{
> +	return (n != 0 && ((n & (n - 1)) == 0));
> +}
> +
> +/*
>   * round up to nearest power of two
>   */
>  static inline __attribute__((const))


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