reactos/lib/rtl/bit.c

   1 /* COPYRIGHT:       See COPYING in the top level directory
   2  * PROJECT:         ReactOS system libraries
   3  * FILE:            lib/rtl/bit.c
   4  * PROGRAMER:       Eric Kohl
   5  */
   6
   7 /* INCLUDES *****************************************************************/
   8
   9 #include <rtl.h>
  10
  11 #define NDEBUG
  12 #include <debug.h>
  13
  14 /* FUNCTIONS ****************************************************************/
  15
  16 /*
  17  * @implemented
  18  */
  19 CCHAR NTAPI
  20 RtlFindLeastSignificantBit(IN ULONGLONG Set)
  21 {
  22   int i;
  23
  24   if (Set == 0ULL)
  25     return -1;
  26
  27   for (i = 0; i < 64; i++)
  28   {
  29     if (Set & (1 << i))
  30       return (CCHAR)i;
  31   }
  32
  33   return -1;
  34 }
  35
  36
  37 /*
  38  * @implemented
  39  */
  40 CCHAR NTAPI
  41 RtlFindMostSignificantBit(IN ULONGLONG Set)
  42 {
  43   int i;
  44
  45   if (Set == 0ULL)
  46     return -1;
  47
  48   for (i = 63; i >= 0; i--)
  49   {
  50     if (Set & (1 << i))
  51       return (CCHAR)i;
  52   }
  53
  54   return -1;
  55 }
  56
  57 /* EOF */