sdk/lib/rtl/byteswap.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS system libraries
   4  * FILE:            lib/rtl/byteswap.c
   5  * PURPOSE:         Memory functions
   6  * PROGRAMMER:      David Welch (welch@mcmail.com)
   7  */
   8
   9 /* INCLUDES *****************************************************************/
  10
  11 #include <rtl.h>
  12
  13 #define NDEBUG
  14 #include <debug.h>
  15
  16 #if defined(_M_IX86)
  17 /* RtlUlonglongByteSwap is broken and cannot be done in C on x86 */
  18 #error "Use rtlswap.S!"
  19 #endif
  20
  21 #undef RtlUlonglongByteSwap
  22 #undef RtlUlongByteSwap
  23 #undef RtlUshortByteSwap
  24
  25 /*************************************************************************
  26  * RtlUshortByteSwap
  27  *
  28  * Swap the bytes of an unsigned short value.
  29  *
  30  * NOTES
  31  * Based on the inline versions in Wine winternl.h
  32  *
  33  * @implemented
  34  */
  35 USHORT
  36 FASTCALL
  37 RtlUshortByteSwap(
  38     IN USHORT Source)
  39 {
  40 #if defined(_M_AMD64)
  41     return _byteswap_ushort(Source);
  42 #else
  43     return (Source >> 8) | (Source << 8);
  44 #endif
  45 }
  46
  47
  48
  49 /*************************************************************************
  50  * RtlUlongByteSwap    [NTDLL.@]
  51  *
  52  * Swap the bytes of an unsigned int value.
  53  *
  54  * NOTES
  55  * Based on the inline versions in Wine winternl.h
  56  *
  57  * @implemented
  58  */
  59 ULONG
  60 FASTCALL
  61 RtlUlongByteSwap(
  62    IN ULONG Source)
  63 {
  64 #if defined(_M_AMD64)
  65     return _byteswap_ulong(Source);
  66 #else
  67     return ((ULONG)RtlUshortByteSwap((USHORT)Source) << 16) | RtlUshortByteSwap((USHORT)(Source >> 16));
  68 #endif
  69 }
  70
  71
  72 /*************************************************************************
  73  * RtlUlonglongByteSwap
  74  *
  75  * Swap the bytes of an unsigned long long value.
  76  *
  77  * PARAMS
  78  *  i [I] Value to swap bytes of
  79  *
  80  * RETURNS
  81  *  The value with its bytes swapped.
  82  *
  83  * @implemented
  84  */
  85 ULONGLONG FASTCALL
  86 RtlUlonglongByteSwap(
  87     IN ULONGLONG Source)
  88 {
  89 #if defined(_M_AMD64)
  90     return _byteswap_uint64(Source);
  91 #else
  92     return ((ULONGLONG) RtlUlongByteSwap (Source) << 32) | RtlUlongByteSwap (Source>>32);
  93 #endif
  94 }
  95
  96
  97 /* EOF */