Re: [PATCH] Staging: emxx_udc: fix warning "sum of probable bitmasks, consider |"
From: Dan Carpenter
Date: Thu Jun 06 2019 - 06:55:41 EST
On Wed, Jun 05, 2019 at 12:04:43PM +0530, Hariprasad Kelam wrote:
> On Mon, Jun 03, 2019 at 09:04:57PM +0200, Greg Kroah-Hartman wrote:
> > On Tue, Jun 04, 2019 at 12:24:12AM +0530, Hariprasad Kelam wrote:
> > > Knowing the fact that operator '|' is faster than '+'.
> > > Its better we replace + with | in this case.
> > >
> > > Issue reported by coccicheck
> > > drivers/staging/emxx_udc/emxx_udc.h:94:34-35: WARNING: sum of probable
> > > bitmasks, consider |
> > >
> > > Signed-off-by: Hariprasad Kelam <hariprasad.kelam@xxxxxxxxx>
> > > ---
> > > drivers/staging/emxx_udc/emxx_udc.h | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/staging/emxx_udc/emxx_udc.h b/drivers/staging/emxx_udc/emxx_udc.h
> > > index b8c3dee..88d6bda 100644
> > > --- a/drivers/staging/emxx_udc/emxx_udc.h
> > > +++ b/drivers/staging/emxx_udc/emxx_udc.h
> > > @@ -91,7 +91,7 @@ int vbus_irq;
> > > #define BIT30 0x40000000
> > > #define BIT31 0x80000000
> > All of those BITXX defines should be removed and the "real" BIT(X) macro
> > used instead.
> Yes will send separate patch to address this.
> > > -#define TEST_FORCE_ENABLE (BIT18 + BIT16)
> > > +#define TEST_FORCE_ENABLE (BIT18 | BIT16)
> > It really doesn't matter, a good compiler will have already turned this
> > into a constant value so you really do not know if this is less/faster
> > code or not, right?
> > Did you look at the output to verify this actually changed anything?
> > thanks,
> > greg k-h
> Ok . Treating this as false postive from coccicheck.
I liked the patch. | is way more normal and readable than +. It's just
the commit message was bogus.
I would be very surprised if this coccicheck found anything that wasn't
a compile time constant like this.