#ifndef _NTRTL_H
NTSYSAPI
CCHAR
NTAPI
RtlFindMostSignificantBit(
_In_ ULONGLONG Set
);
View code on GitHub// wdm.h
NTSYSAPI CCHAR RtlFindMostSignificantBit(
[in] ULONGLONG Set
);
View the official Windows Driver Kit DDI referenceThis function is documented in Windows Driver Kit.
The RtlFindMostSignificantBit routine returns the zero-based position of the most significant nonzero bit in its parameter.
Set [in]The 64-bit value to be searched for its most significant nonzero bit.
The zero-based bit position of the most significant nonzero bit, or -1 if every bit is zero.