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SubjectRe: [PATCH] lib: Fix bug in int_sqrt() for 64 bit longs
Peter Williams a écrit :
> The implementation of int_sqrt() assumes that longs have 32 bits. On
> systems that have 64 bit longs this will result in gross errors when the
> argument to the function is greater than 2^32 - 1 on such systems. I
> doubt whether any such use is currently made of int_sqrt() but the
> attached patch fixes the problem anyway.
>
> Signed-off-by: Peter Williams <pwil3058@bigpond.com.au>
>
>
> ------------------------------------------------------------------------
>
> Index: GIT-warnings/lib/int_sqrt.c
> ===================================================================
> --- GIT-warnings.orig/lib/int_sqrt.c 2005-10-25 13:55:22.000000000 +1000
> +++ GIT-warnings/lib/int_sqrt.c 2006-01-06 14:29:19.000000000 +1100
> @@ -15,7 +15,7 @@ unsigned long int_sqrt(unsigned long x)
> op = x;
> res = 0;
>
> - one = 1 << 30;
> + one = 1 << (BITS_PER_LONG - 2);
> while (one > op)
> one >>= 2;
>

Are you sure it works ?

I would have writen :

one = 1L << (BITS_PER_LONG - 2);

Eric
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