4.3BSD - /usr/ingres/source/gutil/bitpos.c

   1: # include   <sccs.h>
   2: 
   3: SCCSID(@(#)bitpos.c	8.1	12/31/84)
   4: 
   5: /*
   6: **  FIND HIGH ORDER BIT POSITION
   7: **
   8: **	The position of the highest ordered one bit in `wd' is
   9: **	found and returned.  Bits are numbered 0 -> 15, from
  10: **	right (low-order) to left (high-order) in word.
  11: */
  12: 
  13: bitpos(wd)
  14: register int    wd;
  15: {
  16:     register int    i, j;
  17:     register int    pos;
  18: 
  19:     pos = -1;
  20: 
  21:     for (i = 1, j = 0; wd; i <<= 1, j++)
  22:     {
  23:         if (wd & i)
  24:         {
  25:             pos = j;
  26:             wd &= ~i;
  27:         }
  28:     }
  29: 
  30:     return (pos);
  31: }

Defined functions