94 lines
2.3 KiB
C
94 lines
2.3 KiB
C
/***
|
|
*rotr.c - rotate an unsigned integer right
|
|
*
|
|
* Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.
|
|
*
|
|
*Purpose:
|
|
* defines _rotr() - performs a rotate right 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
|
|
* <cruntime.h> 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 rotr functions and added __int64 version.
|
|
*
|
|
*******************************************************************************/
|
|
|
|
#ifndef _POSIX_
|
|
|
|
#include <cruntime.h>
|
|
#include <stdlib.h>
|
|
#include <limits.h>
|
|
|
|
#ifdef _MSC_VER
|
|
#pragma function(_lrotr,_rotr, _rotr64)
|
|
#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 _rotr(val, shift) - int rotate right
|
|
*
|
|
*Purpose:
|
|
* Performs a rotate right 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 _lrotr (
|
|
unsigned long val,
|
|
int shift
|
|
)
|
|
{
|
|
shift &= 0x1f;
|
|
val = (val<<(0x20 - shift)) | (val >> shift);
|
|
return val;
|
|
}
|
|
|
|
unsigned __cdecl _rotr (
|
|
unsigned val,
|
|
int shift
|
|
)
|
|
{
|
|
shift &= 0x1f;
|
|
val = (val<<(0x20 - shift)) | (val >> shift);
|
|
return val;
|
|
}
|
|
|
|
unsigned __int64 __cdecl _rotr64 (
|
|
unsigned __int64 val,
|
|
int shift
|
|
)
|
|
{
|
|
shift &= 0x3f;
|
|
val = (val<<(0x40 - shift)) | (val >> shift);
|
|
return val;
|
|
}
|
|
#endif
|