[CRT] fix bug in _rotr implementation
[reactos.git] / sdk / lib / crt / stdlib / rot.c
1 /*
2 * COPYRIGHT: See COPYING in the top level directory
3 * PROJECT: ReactOS system libraries
4 * FILE: lib/sdk/crt/stdlib/rot.c
5 * PURPOSE: Performs a bitwise rotation
6 * PROGRAMER: Ariadne
7 * UPDATE HISTORY:
8 * 03/04/99: Created
9 */
10
11 #include <stdlib.h>
12
13 #ifdef _MSC_VER
14 #pragma function(_rotr, _rotl, _rotr, _lrotl, _lrotr)
15 #endif
16
17 unsigned int _rotr( unsigned int value, int shift );
18 /*
19 * @implemented
20 */
21 unsigned int _rotl( unsigned int value, int shift )
22 {
23 int max_bits = sizeof(unsigned int)<<3;
24 if ( shift < 0 )
25 return _rotr(value,-shift);
26
27 if ( shift > max_bits )
28 shift = shift % max_bits;
29 return (value << shift) | (value >> (max_bits-shift));
30 }
31
32 /*
33 * @implemented
34 */
35 unsigned int _rotr( unsigned int value, int shift )
36 {
37 int max_bits = sizeof(unsigned int)<<3;
38 if ( shift < 0 )
39 return _rotl(value,-shift);
40
41 if ( shift > max_bits )
42 shift = shift % max_bits;
43 return (value >> shift) | (value << (max_bits-shift));
44 }
45
46
47 /*
48 * @implemented
49 */
50 unsigned long _lrotl( unsigned long value, int shift )
51 {
52 int max_bits = sizeof(unsigned long)<<3;
53 if ( shift < 0 )
54 return _lrotr(value,-shift);
55
56 if ( shift > max_bits )
57 shift = shift % max_bits;
58 return (value << shift) | (value >> (max_bits-shift));
59 }
60
61 /*
62 * @implemented
63 */
64 unsigned long _lrotr( unsigned long value, int shift )
65 {
66 int max_bits = sizeof(unsigned long)<<3;
67 if ( shift < 0 )
68 return _lrotl(value,-shift);
69
70 if ( shift > max_bits )
71 shift = shift % max_bits;
72 return (value >> shift) | (value << (max_bits-shift));
73 }