Re: [PATCH] make jiffies wrap 5 min after boot

Falk Hueffner
2003-02-16T11:41:04Z

Muli Ben-Yehuda <mulix@mulix.org> writes:

> On Sun, Feb 16, 2003 at 01:37:40AM -0500, Robert Love wrote:
> > On Sat, 2003-02-15 at 21:43, William Lee Irwin III wrote:
> >
> > > Can I get a vote for ~0UL instead of -1UL?
> >
> > OK, I bite. What is the difference? Aren't both equivalent?
>
> I have no idea if that's what wli meant, but -1UL is only "all ones"
> in a 2's complement binary representation.

No. Wraparound of unsigned types is well-defined. -1UL must be the
largest possible unsigned long value, which must consist of only 1
bits (except for possible padding bits).

Of course, no machines with ones-complement (or padding bits, or
integer trap representations, or any of the other ISO braindamages)
exist, so this is mostly irrelevant anyway.

--
Falk