Re: [XEN PATCH][for-4.19 1/9] xen/include: add macro LOWEST_POW2

[Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>]

On 06/10/2023 18:35, andrew.cooper3@xxxxxxxxxx wrote:
> On 06/10/2023 9:26 am, Nicola Vetrini wrote:
> > diff --git a/xen/include/xen/macros.h b/xen/include/xen/macros.h
> > index d0caae7db298..bb9a1c9a53d0 100644
> > --- a/xen/include/xen/macros.h
> > +++ b/xen/include/xen/macros.h
> > @@ -8,8 +8,10 @@
> >  #define DIV_ROUND(n, d) (((n) + (d) / 2) / (d))
> >  #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
> >
> > -#define MASK_EXTR(v, m) (((v) & (m)) / ((m) & -(m)))
> > -#define MASK_INSR(v, m) (((v) * ((m) & -(m))) & (m))
> > +#define LOWEST_POW2(x) ((x) & -(x))
> Naming wise, LOWEST_BIT() please.
>
> The fact it's a power of two is incidental, and POW2 is ambiguous,
> because it includes interpretations such as "calculate the lowest power
> of two greater than x".
>
> ~Andrew
You have a point. I'll change it.

--
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)