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 __clang__
14 # define _rotl __function_rotl
15 # define _rotr __function_rotr
16 # define _lrotl __function_lrotl
17 # define _lrotr __function_lrotr
18 #elif defined(_MSC_VER)
19 # pragma function(_rotr, _rotl, _rotr, _lrotl, _lrotr)
20 #endif
21
22 #if defined (__clang__) && !defined(_MSC_VER)
23 # ifdef _M_IX86
24 unsigned int _rotr( unsigned int value, int shift ) __asm__("__rotr");
25 unsigned long _lrotr(unsigned long value, int shift) __asm__("__lrotr");
26 unsigned int _rotl( unsigned int value, int shift ) __asm__("__rotl");
27 unsigned long _lrotl( unsigned long value, int shift ) __asm__("__lrotl");
28 # else
29 unsigned int _rotr( unsigned int value, int shift ) __asm__("_rotr");
30 unsigned long _lrotr(unsigned long value, int shift) __asm__("_lrotr");
31 unsigned int _rotl( unsigned int value, int shift ) __asm__("_rotl");
32 unsigned long _lrotl( unsigned long value, int shift ) __asm__("_lrotl");
33 # endif
34 #else
35 unsigned int _rotr( unsigned int value, int shift );
36 unsigned long _lrotr(unsigned long value, int shift);
37 unsigned int _rotl( unsigned int value, int shift );
38 unsigned long _lrotl( unsigned long value, int shift );
39 #endif
40 /*
41 * @implemented
42 */
_rotl(unsigned int value,int shift)43 unsigned int _rotl( unsigned int value, int shift )
44 {
45 int max_bits = sizeof(unsigned int)<<3;
46 if ( shift < 0 )
47 return _rotr(value,-shift);
48
49 if ( shift > max_bits )
50 shift = shift % max_bits;
51 return (value << shift) | (value >> (max_bits-shift));
52 }
53
54 /*
55 * @implemented
56 */
_rotr(unsigned int value,int shift)57 unsigned int _rotr( unsigned int value, int shift )
58 {
59 int max_bits = sizeof(unsigned int)<<3;
60 if ( shift < 0 )
61 return _rotl(value,-shift);
62
63 if ( shift > max_bits )
64 shift = shift % max_bits;
65 return (value >> shift) | (value << (max_bits-shift));
66 }
67
68 /*
69 * @implemented
70 */
_lrotl(unsigned long value,int shift)71 unsigned long _lrotl( unsigned long value, int shift )
72 {
73 int max_bits = sizeof(unsigned long)<<3;
74 if ( shift < 0 )
75 return _lrotr(value,-shift);
76
77 if ( shift > max_bits )
78 shift = shift % max_bits;
79 return (value << shift) | (value >> (max_bits-shift));
80 }
81
82 /*
83 * @implemented
84 */
_lrotr(unsigned long value,int shift)85 unsigned long _lrotr( unsigned long value, int shift )
86 {
87 int max_bits = sizeof(unsigned long)<<3;
88 if ( shift < 0 )
89 return _lrotl(value,-shift);
90
91 if ( shift > max_bits )
92 shift = shift % max_bits;
93 return (value >> shift) | (value << (max_bits-shift));
94 }
95