Function MostSignificantBitCT

util/generic/bitops.h:320–322

* Returns 0 - based position of the most significant bit (compile time) * 0 for 0. */

 * 0 for 0.
 */
constexpr ui64 MostSignificantBitCT(ui64 x) {
    return x > 1 ? 1 + MostSignificantBitCT(x >> 1) : 0;
}

/*
 * Return rounded up binary logarithm of `x`.