Re: [KJ][RFC][PATCH] BIT macro cleanup

[Vojtech Pavlik]

On Fri, Feb 23, 2007 at 01:44:41PM +0530, Milind Choudhary wrote:
> Hi all
> 	working towards the cleanup of BIT macro,
> I've added one to <linux/bitops.h> & cleaned some obvious users.
> 
> include/linux/input.h also has a BIT macro
> which does a wrap
> so currently i've done something like
> 
> +#undef BIT
> #define BIT(nr)        (1UL << ((nr) % BITS_PER_LONG))
 
Since the previous definition of

#define BIT(nr)		(1UL << (nr))

gives the same results as the above one for all reasonable usage
scenarios (you don't want to supply nr larger than BITS_PER_LONG),
why not just use the modulo version everywhere?

The only problem I see is that the compiler would not warn where nr IS
too large.

-- 
Vojtech Pavlik
Director SuSE Labs
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