Re: [PATCH 2.6.20] isdn-capi: Use ARRAY_SIZE macro when appropriate

[Bill Davidsen <davidsen@tmr.com>]

Philippe De Muyter wrote:
> On Tue, Feb 06, 2007 at 10:41:30PM +0200, Ahmed S. Darwish wrote:
> > On Tue, Feb 06, 2007 at 09:52:17AM -0800, Joe Perches wrote:
> > > On Tue, 2007-02-06 at 18:04 +0200, Ahmed S. Darwish wrote:
> > > > A patch to use ARRAY_SIZE macro already defined in kernel.h
> > > > Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
> > [...]
> > > > -    int nelem = sizeof(procfsentries)/sizeof(procfsentries[0]);
> > > > +    int nelem = ARRAY_SIZE(procfsentries);
> > > >      int i;
> > > >  
> > > >      for (i=0; i < nelem; i++) {
> > > For these patches, perhaps you can eliminate the temporary
> > > variable and change the loop to the more common form of
> > >
> > > 	for (i = 0; i < ARRAY_SIZE(array); i++) {
> > Thanks, I think it's better too. Here's the modified patch.
> >
> > A patch to use ARRAY_SIZE macro when appropriate.
> >
> > Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
> > ---
> > diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
> > index d22c022..87fe89c 100644
> > --- a/drivers/isdn/capi/capi.c
> > +++ b/drivers/isdn/capi/capi.c
> > @@ -1456,10 +1456,9 @@ static struct procfsentries {
> >  
> >  static void __init proc_init(void)
> >  {
> > -    int nelem = sizeof(procfsentries)/sizeof(procfsentries[0]);
> >      int i;
> >  
> > -    for (i=0; i < nelem; i++) {
> > +    for (i = 0; i < ARRAY_SIZE(procfsentries); i++) {
> >          struct procfsentries *p = procfsentries + i;
> >  	p->procent = create_proc_entry(p->name, p->mode, NULL);
> >  	if (p->procent) p->procent->read_proc = p->read_proc;
> > @@ -1468,10 +1467,9 @@ static void __init proc_init(void)
> >  
> >  static void __exit proc_exit(void)
> >  {
> > -    int nelem = sizeof(procfsentries)/sizeof(procfsentries[0]);
> >      int i;
> >  
> > -    for (i=nelem-1; i >= 0; i--) {
> > +    for (i = ARRAY_SIZE(procfsentries) - 1; i >= 0; i--) {
>
> I would write such decrementing loops as :
>
>        for (i = ARRAY_SIZE(procfsentries); --i >= 0; ) {
>
> Long time ago, that produced better code.  I did not check recently though.

Why would you write "--i >= 0" instead of just "i--"? The size of an 
array can't be negative.

--
Bill Davidsen <davidsen@tmr.com>
  "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot
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