Re: [PATCH] Make is_signed_type() simpler

From: Alexey Dobriyan
Date: Sun Sep 29 2019 - 17:09:47 EST


On Sun, Sep 29, 2019 at 10:21:48PM +0200, Rasmus Villemoes wrote:
> On 29/09/2019 22.06, Alexey Dobriyan wrote:
> > * Simply compare -1 with 0,
> > * Drop unnecessary parenthesis sets
> >
> > -#define is_signed_type(type) (((type)(-1)) < (type)1)
> > +#define is_signed_type(type) ((type)-1 < 0)
>
> NAK. I wrote it that way to avoid -Wtautological-compare when type is
> unsigned.

Was is W=1?

godbolt doesn't show it with just -Wall

https://godbolt.org/z/kCA7mm

And the warning which found i915 case is -Wextra not -Wtautological-compare.