mirror of
https://github.com/reactos/reactos.git
synced 2024-08-24 04:08:38 +00:00
74 lines
1.5 KiB
C
74 lines
1.5 KiB
C
/*
|
|
* COPYRIGHT: See COPYING in the top level directory
|
|
* PROJECT: ReactOS system libraries
|
|
* FILE: lib/sdk/crt/stdlib/rot.c
|
|
* PURPOSE: Performs a bitwise rotation
|
|
* PROGRAMER: Ariadne
|
|
* UPDATE HISTORY:
|
|
* 03/04/99: Created
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
|
|
#ifdef _MSC_VER
|
|
#pragma function(_rotr, _rotl, _rotr, _lrotl, _lrotr)
|
|
#endif
|
|
|
|
unsigned int _rotr( unsigned int value, int shift );
|
|
/*
|
|
* @implemented
|
|
*/
|
|
unsigned int _rotl( unsigned int value, int shift )
|
|
{
|
|
int max_bits = sizeof(unsigned int)<<3;
|
|
if ( shift < 0 )
|
|
return _rotr(value,-shift);
|
|
|
|
if ( shift > max_bits )
|
|
shift = shift % max_bits;
|
|
return (value << shift) | (value >> (max_bits-shift));
|
|
}
|
|
|
|
/*
|
|
* @implemented
|
|
*/
|
|
unsigned int _rotr( unsigned int value, int shift )
|
|
{
|
|
int max_bits = sizeof(unsigned int)<<3;
|
|
if ( shift < 0 )
|
|
return _rotl(value,-shift);
|
|
|
|
if ( shift > max_bits<<3 )
|
|
shift = shift % max_bits;
|
|
return (value >> shift) | (value << (max_bits-shift));
|
|
}
|
|
|
|
|
|
/*
|
|
* @implemented
|
|
*/
|
|
unsigned long _lrotl( unsigned long value, int shift )
|
|
{
|
|
int max_bits = sizeof(unsigned long)<<3;
|
|
if ( shift < 0 )
|
|
return _lrotr(value,-shift);
|
|
|
|
if ( shift > max_bits )
|
|
shift = shift % max_bits;
|
|
return (value << shift) | (value >> (max_bits-shift));
|
|
}
|
|
|
|
/*
|
|
* @implemented
|
|
*/
|
|
unsigned long _lrotr( unsigned long value, int shift )
|
|
{
|
|
int max_bits = sizeof(unsigned long)<<3;
|
|
if ( shift < 0 )
|
|
return _lrotl(value,-shift);
|
|
|
|
if ( shift > max_bits )
|
|
shift = shift % max_bits;
|
|
return (value >> shift) | (value << (max_bits-shift));
|
|
}
|