ot be specified exactly, since the hardware representation relies on 
			powers-of-two bitmasks. The perfmon library tries to optimize the alignment of 
			these power-of-two regions to cover the addresses requested as effectively as 
			possible with the four sets of registers available. Perfmon first finds the 
			largest power-of-two address region completely contained within the reqested 
			addresses. Then it finds successively smaller power-of-two regions to cover the 
			errors on the high and low en