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SubjectRe: [RFC][PATCH] fix abs() macro to work with types wider than int
On Thu, 19 Apr 2007 11:23:39 +0200 Jiri Bohac wrote:

> Hi,
>
> is there any reason to use an explicit int instead of a typeof in
> the abs() macro? The current implementation will return bogus
> results when used with longs.

I think it's like it is just to be consistent with abs() in C,
which also contains labs() and llabs().

> How about changing the int to a typeof like this?:
>
>
>
> Fix the abs() macro to work with wider types than int.
>
> Signed-off-by: Jiri Bohac <jbohac@suse.cz>
>
> --- linux-2.6.21-rc5.orig/include/linux/kernel.h
> +++ linux-2.6.21-rc5/include/linux/kernel.h
> @@ -89,7 +89,7 @@ extern int cond_resched(void);
> #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
>
> #define abs(x) ({ \
> - int __x = (x); \
> + typeof(x) __x = (x); \
> (__x < 0) ? -__x : __x; \
> })
>
>
>
>
> --
> Jiri Bohac <jbohac@suse.cz>
> SUSE Labs, SUSE CZ

---
~Randy
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