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 __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  */
  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  */
  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  */
  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  */
  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 }