/*** *rotl.c - rotate an unsigned integer left * * Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved. * *Purpose: * defines _rotl() - performs a rotate left on an unsigned integer. * *Revision History: * 06-02-89 PHG Module created * 11-03-89 JCR Added _lrotl * 03-15-90 GJF Made calling type _CALLTYPE1, added #include * and fixed the copyright. Also, cleaned * up the formatting a bit. * 10-04-90 GJF New-style function declarators. * 04-01-91 SRW Enable #pragma function for i386 _WIN32_ builds too. * 09-02-92 GJF Don't build for POSIX. * 04-06-93 SKS Replace _CRTAPI* with __cdecl * No _CRTIMP for CRT DLL model due to intrinsic * 12-03-93 GJF Turn on #pragma function for all MS front-ends (esp., * Alpha compiler). * 01-04-01 GB Rewrote rotl functions and added __int64 version. * *******************************************************************************/ #ifndef _POSIX_ #include #include #include #ifdef _MSC_VER #pragma function(_lrotl,_rotl, _rotl64) #endif #if UINT_MAX != 0xffffffff /*IFSTRIP=IGN*/ #error This module assumes 32-bit integers #endif #if UINT_MAX != ULONG_MAX /*IFSTRIP=IGN*/ #error This module assumes sizeof(int) == sizeof(long) #endif /*** *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; } #endif