I am working on a project and I need to calculate the least significant bit (LSB) and most significant bit (MSB) of integers.
Suppose $x$ is an $n$-bit unsigned integer ($n=16, 32$ or $64$). We know that $y=x \ \& \ ($~$x+1)$ clears all the bits of $x$ except for the LSB. This is lightning fast, just three operations. Is there something similar for the MSB? What is the fastest way to compute it?