reactos/sdk/lib/ucrt/stdlib/rotr.cpp

//
// rotr.cpp
//
//      Copyright (c) Microsoft Corporation. All rights reserved.
//
// Defines _lrotl(), _rotl(), and _rotl64(), which perform a rotate-right on an
// integer.
//
#include <stdlib.h>
#include <limits.h>



#pragma function(_lrotr, _rotr, _rotr64)

#if UINT_MAX != 0xffffffff
    #error This source file assumes 32-bit integers
#endif

#if UINT_MAX != ULONG_MAX
    #error This source file assumes sizeof(int) == sizeof(long)
#endif



extern "C" unsigned long __cdecl _lrotr(unsigned long value, int shift)
{
    shift &= 0x1f;
    value = (value << (0x20 - shift)) | (value >> shift);
    return value;
}

extern "C" unsigned __cdecl _rotr(unsigned value, int shift)
{
    shift &= 0x1f;
    value = (value << (0x20 - shift)) | (value >> shift);
    return value;
}

extern "C" unsigned __int64 __cdecl _rotr64(unsigned __int64 value, int shift)
{
    shift &= 0x3f;
    value = (value << (0x40 - shift)) | (value >> shift);
    return value;
}