Re: Subtracting unsigned entities

fred.l.kleinschmidt@[EMAIL PROTECTED]
 writes:

> If one knows that x and y are unsigned integers (of unknown size -
> they may be short, int, long, long long), what is the most ****table
> way to determine their difference?
>
> If x is smaller than y, then x-y is negative.

Mathematically, yes.  But in C, the difference of two values of
type unsigned int is always nonnegative.

> A naive approach is
>    if ( x > y ) {
>       ...
>    }
>
> but a compiler may code (x>y) as  (x-y > 0).

No, the compiler is obliged to produce the correct result.
-- 
"The way I see it, an intelligent person who disagrees with me is
 probably the most im****tant person I'll interact with on any given
 day."
--Billy Chambless