2019-06-03 18:57:36

by Hariprasad Kelam

Subject: [PATCH] Staging: emxx_udc: fix warning "sum of probable bitmasks, consider |"

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 <[email protected]>
---
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

-#define TEST_FORCE_ENABLE (BIT18 + BIT16)
+#define TEST_FORCE_ENABLE (BIT18 | BIT16)

#define INT_SEL BIT10
#define CONSTFS BIT09
--
2.7.4

2019-06-03 19:08:03

by Greg Kroah-Hartman

Subject: Re: [PATCH] Staging: emxx_udc: fix warning "sum of probable bitmasks, consider |"

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 <[email protected]>
> ---
> 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.

> -#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

2019-06-05 06:36:38

by Hariprasad Kelam

Subject: Re: [PATCH] Staging: emxx_udc: fix warning "sum of probable bitmasks, consider |"

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 <[email protected]>
> > ---
> > 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.

Thanks,
Hariprasad k

2019-06-06 12:09:11

by Dan Carpenter

Subject: Re: [PATCH] Staging: emxx_udc: fix warning "sum of probable bitmasks, consider |"

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 <[email protected]>
> > > ---
> > > 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.

regards,
dan carpenter