Re: [PATCH v2 3/9] bitops: Introduce a more generic BITMASK macro

Joe Perches
2013-10-17T08:55:16Z

On Thu, 2013-10-17 at 10:40 +0200, Borislav Petkov wrote:
> On Thu, Oct 17, 2013 at 01:32:30AM -0700, Joe Perches wrote:
> > On Thu, 2013-10-17 at 03:38 -0400, Chen Gong wrote:
> > > the point is we can use GENMASK like GENMASK(end_bit, start_bit) but
> > > we don't know the value of end_bit/start_bit at compile-time.
> >
> > True.
> >
> > The BUILD_BUG_ON idea is just to avoid people using
> > GENMASK(1, 2)
>
> They'll notice the 0 pretty quickly when they test their code.
>
> Let's add those checks only when it is really necessary and people have
> actually made that mistake repeatedly.

It's cost free to add the BUILD_BUG_ON
and perhaps you underestimate the runtime
bug checking effort,