2010/8/2 john gilmore <[email protected]>: > The question--What use are one-bit counts for a bit string?--would occur only > to someone who was unfamiliar with bit maps and their uses.
I'm devastated to find myself revealed as a complete moron in front of my peers by asking such a silly question. 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. While I see that it would help to count the free slots in an allocation map, you'd certainly hope that the code that updates the bitmap also keeps counters so that we don't have to count the bits too often. And one could compute parity, but I'm not sure that's often done on long strings anymore. | Rob
