Re: + fls-change-parameter-to-unsigned-int.patch added to -mm tree

From: Matthew Wilcox
Date: Tue Nov 06 2018 - 10:44:39 EST


On Tue, Nov 06, 2018 at 06:14:44PM +0300, Alexey Dobriyan wrote:
> On Mon, Nov 05, 2018 at 03:33:01PM -0800, akpm@xxxxxxxxxxxxxxxxxxxx wrote:
>
> > -static inline int fls(int x)
> > +static inline int fls(unsigned int x)
> > {
> > - return fls64((unsigned int) x);
> > + return fls64(x);
> > }
>
> Should it return "unsigned"? Logically it should.
> I remember doing this and there was some code size increase :-(

Yes, it returns a number in the range [0-32], so it can absolutely
be unsigned. I'm kind of surprised it made any difference.

When you say "doing this", what did you try? unsigned fls(unsigned),
int fls(unsigned) or unsigned fls(int) ?