Re: [PATCH -mm] Introduce U16_MAX and U32_MAX

[Satyam Sharma <satyam@infradead.org>]

On Tue, 31 Jul 2007, Andrew Morton wrote:

> On Tue, 31 Jul 2007 21:56:12 +0530 (IST)
> Satyam Sharma <satyam@infradead.org> wrote:
> 
> > --- a/include/linux/kernel.h
> > +++ b/include/linux/kernel.h
> > @@ -30,6 +30,9 @@ extern const char linux_proc_banner[];
> >  #define LLONG_MIN	(-LLONG_MAX - 1)
> >  #define ULLONG_MAX	(~0ULL)
> >  
> > +#define U16_MAX		((u16) ~0U)
> > +#define U32_MAX		((u32) ~0U)
> > +
> 
> hm, I'd have thought that there's a risk of gcc warnings here, forcing
> 0xffffffff into a u16, but apparently not.
> 
> Still, I think it'd be tidier here to tell the truth and use plain
> old 0xffff and 0xffffffff?

Hmm, that does make sense, actually -- in fact that's the only _really_
correct way to define u32_max / u16_max, I'd say. I probably got confused
seeing those bad examples in reiserfs and tcp_illinois ;-)

Thanks.