public static long ulpDistance(final double a, final double b) {
		return Math.subtractExact(ulpPosition(a), ulpPosition(b));
	}
Return the <a href="http://en.wikipedia.org/wiki/Unit_in_the_last_place">ULP</a>
distance of the given two double values.

@param a first double.
@param b second double.
@return the ULP distance.
@throws ArithmeticException if the distance doesn't fit in a long value.
jenetics/src/main/java/io/jenetics/internal/math/Basics.java