/*** *rotl.c - rotate an unsigned integer left * * Copyright (c) Microsoft Corporation. All rights reserved. * *Purpose: * defines _rotl() - performs a rotate left on an unsigned integer. * *******************************************************************************/ #include #include #include #ifdef _MSC_VER #pragma function(_lrotl,_rotl, _rotl64) #endif /* _MSC_VER */ #if UINT_MAX != 0xffffffff #error This module assumes 32-bit integers #endif /* UINT_MAX != 0xffffffff */ #if UINT_MAX != ULONG_MAX #error This module assumes sizeof(int) == sizeof(long) #endif /* UINT_MAX != ULONG_MAX */ /*** *unsigned _rotl(val, shift) - int rotate left * *Purpose: * Performs a rotate left on an unsigned integer. * * [Note: The _lrotl entry is based on the assumption * that sizeof(int) == sizeof(long).] *Entry: * unsigned val: value to rotate * int shift: number of bits to shift by * *Exit: * returns rotated value * *Exceptions: * None. * *******************************************************************************/ unsigned long __cdecl _lrotl ( unsigned long val, int shift ) { shift &= 0x1f; val = (val>>(0x20 - shift)) | (val << shift); return val; } unsigned __cdecl _rotl ( unsigned val, int shift ) { shift &= 0x1f; val = (val>>(0x20 - shift)) | (val << shift); return val; } unsigned __int64 __cdecl _rotl64 ( unsigned __int64 val, int shift ) { shift &= 0x3f; val = (val>>(0x40 - shift)) | (val << shift); return val; }