value range propagation for _bitwise_ OR

[Andrei Alexandrescu]

On 04/11/2010 09:18 PM, Adam D. Ruppe wrote:
> On Sun, Apr 11, 2010 at 10:00:41PM -0400, Steven Schveighoffer wrote:
>> We are talking about range propagation, a function of the compiler, not a function of the compiled program.  Therefore, slower but more exact functions should be preferred, since they only affect the compile time.
>
> I agree with this. While my solution has a certain beauty to it and is
> fast, your solution accurately covers all the bases, whereas mine fails with
> min>  1. I say we go with your's.

Agreed. Steve's solution is the best we have for unsigned numbers.

Andrei