Re: [PATCH 03/11] Task watchers: Refactor process events

Chase Venters
2006-06-14T08:10:01Z

On Tuesday 13 June 2006 20:11, Matt Helsley wrote:
> On Tue, 2006-06-13 at 19:43 -0500, Chase Venters wrote:
> > On Tuesday 13 June 2006 18:54, Matt Helsley wrote:
> > > + WARN_ON((which_id != PROC_EVENT_UID) && (which_id !=
> > > PROC_EVENT_GID)); }
> >
> > How about WARN_ON(!(which_id & (PROC_EVENT_UID | PROC_EVENT_GID))) to
> > save a cmp?
> >
> > Thanks,
> > Chase
>
> I think the compiler is capable of making such optimizations. I also
> think what I have now is clearer to anyone skimming the code.

Can the compiler test that (which_id != PROC_EVENT_UID) && (which_id !=
PROC_EVENT_GID) merely by masking? Since they're bits, one mask testing both
could technically match both (true result), which would not happen in the !=
case (false result). It is a small point though.

> Cheers,
> -Matt Helsley

Thanks,
Chase