value range propagation for _bitwise_ OR

[Steven Schveighoffer]

On Mon, 12 Apr 2010 01:11:37 -0400, Rainer Deyke <rainerd at eldwood.com>  
wrote:

> On 4/11/2010 20:51, Steven Schveighoffer wrote:
>> Range propagation is needed to determine if you can put a value into a
>> smaller type.  At that point, all that is needed is the min and max.
>
> Technically, you don't even need min and max at that point.  A bit mask
> would be enough.

Only for unsigned types...

-Steve