Rob van der Heij wrote:
I am well aware of how bit maps are used. However, most legitimate cases I could come up with (like others, apparently) were situations where I would also want to know *which* bit was the first one set (where TRT would be appropriate). Or cases where I'd just want to know that not all bits are on or off. But to have the hardware actually bother to count the bits seems to me pure luxury.
Suppose you are an operating system that must maintain a CPU online/offline mask for all 80 processors on the z196. That's a 10-byte bit string. It might be helpful to be able to quickly count the bits to know how many processors are currently online rather than maintaining a separate field to hold this value. By eliminating this second field, you reduce the possibility to zero that these two different representations of the same information can get out of sync. -- Edward E Jaffe Phoenix Software International, Inc 831 Parkview Drive North El Segundo, CA 90245 310-338-0400 x318 [email protected] http://www.phoenixsoftware.com/
