RtlUshortByteSwap - NtDoc

#ifndef _NTRTL_H
// Byte swap routines.
#ifndef PHNT_RTL_BYTESWAP

#define RtlUshortByteSwap(_x) _byteswap_ushort((USHORT)(_x))

#endif
#endif
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#ifndef _NTRTL_H
// Byte swap routines.
#ifndef PHNT_RTL_BYTESWAP
// ...
#else

NTSYSAPI
USHORT
FASTCALL
RtlUshortByteSwap(
    _In_ USHORT Source
    );

#endif
#endif
View code on GitHub