func math/bits.Len64

3 uses

	math/bits (current package)
		bits.go#L31: func LeadingZeros64(x uint64) int { return 64 - Len64(x) }
		bits.go#L300: 	return Len64(uint64(x))
		bits.go#L331: func Len64(x uint64) (n int) {