Messages in this thread | | | Date | Wed, 25 Apr 2007 08:20:28 -0700 | From | Randy Dunlap <> | Subject | Re: [RFC][PATCH] fix abs() macro to work with types wider than int |
| |
On Fri, 20 Apr 2007 14:44:38 +0200 Richard Knutsson wrote:
> Randy Dunlap wrote: > > 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(). > > > We actually had labs() before (few months ago), but since it was not > used, and if it would it seemed better to just fix abs(), it was > removed. So I think this is the appropriate way to go.
Sounds like when someone actually needs labs() or llabs() they can submit a patch for however they would like to use it.
> >> 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; \ > >> })
--- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code *** - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |