On Tue, Oct 11, 2016 at 12:05:17PM -0600, Jason Gunthorpe wrote:
> On Mon, Oct 10, 2016 at 07:09:30AM +0300, Leon Romanovsky wrote:
>
> > > I think people would complain about the extra stores. gcc 6 will
> > > eliminate them, but older compilers will not.
> >
> > This unintialized_var(x) adds extra store too (... x = x ...).
>
> I have confirmed that the unintialized_var macro does not impact code
> generation on the old gccs while the =0 approach does.

Ohh, thanks.

But I'm still left under impression of this article [1] that using such
macro is a bad thing and we are "punishing" all users of modern compilers.

[1] https://lwn.net/Articles/529954/

>
> So no extra store.
>
> Jason