Re: [PATCH] consolidate all within() implementations
From: Peter 1 Oberparleiter
Date: Wed May 21 2008 - 06:34:06 EST
Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote on 21.05.2008 12:04:26:
> > +static inline int addr_within_len(const void *addr, const void
*start,
> > + size_t len)
> > +{
> > + return ((unsigned long) addr >= (unsigned long) start) &&
> > + ((unsigned long) addr < ((unsigned long) start + len));
> > +}
>
> might be my braindamage, but I'd have written it like:
>
> static inline int
> addr_within_len(const void *addr, const void *start, size_t len)
> {
> return (unsigned long)addr - (unsigned long)start < len;
> }
Definitely another way to put it. In my opinion the intention of the
implementation is more easily understood though when spelling it out
as (a>=b) && (a<c).
> static inline int
> addr_within(const void *add, const void *start, const void *end)
> {
> return addr_within_len(addr, start,
> (unsigned long)end - (unsigned long)start);
> }
For empty ranges (start > end), this produces different (less expected)
results than the previous version.
Regards,
Peter
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