Re: [PATCH] remove abs64()

[Andrew Morton]

On Wed, 13 Apr 2011 00:16:58 +0300
Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:

> On Tue, Apr 12, 2011 at 02:10:40PM -0700, Andrew Morton wrote:
> > On Tue, 12 Apr 2011 14:07:26 -0700
> > Randy Dunlap <rdunlap@xxxxxxxxxxxx> wrote:
> > 
> > > > +	__builtin_choose_expr(						\
> > > > +		__builtin_types_compatible_p(typeof(_x), long long),	\
> > > > +		(unsigned long long)({ _x < 0 ? -_x : _x; }),		\
> > > > +	_x)))));							\
> > > > +})
> > > 
> > > that is better?
> > 
> > I think so.
> > 
> > It's a bit concerning that it changes the return type of abs().
> 
> I haven't read every abs() user, but, yes, sizeof(abs()) silently
> changing is the issue.

It changes signedness_of(abs(signed_expr)) as well.  That changes the
signedness of expressions which use abs() and on and on.
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