Lets say that R=15 and L=8, then how can I efficiently find:
15 XOR 13 XOR 11 XOR 9
If R=20 and L=10, then it would be:
20 XOR 18 XOR 16 XOR 14 XOR 12 XOR 10
$1<=L<=R<=10^{15}$
This might be similiar Finding XOR of all even numbers from n to m but that only covers even numbers. If R is odd then it will be all odd numbers from R to L.
I asked this question on StackOverflow previously but it was marked as duplicate and the problem wasn't exactly the same as this one.