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/*

FUNCTION

        <<ffs>>---find first bit set in a word

INDEX

        ffs

ANSI_SYNOPSIS

        int ffs(int <[word]>);

TRAD_SYNOPSIS

        int ffs(<[word]>);

DESCRIPTION

<<ffs>> returns the first bit set in a word.

RETURNS

<<ffs>> returns 0 if <[c]> is 0, 1 if <[c]> is odd, 2 if <[c]> is a multiple of

2, etc.

PORTABILITY

<<ffs>> is not ANSI C.

No supporting OS subroutines are required.  */

#include <_ansi.h>

int

_DEFUN(ffs, (word),

       int word)

{

  int i;

  if (!word)

    return 0;

  i = 0;

  for (;;)

    {

      if (((1 << i++) & word) != 0)

        return i;

    }

}