Subversion Repositories openrisc_2011-10-31

/* @(#)z_numtest.c 1.0 98/08/13 */

/******************************************************************

 * Numtest

 *

 * Input:

 *   x - pointer to a floating point value

 *

 * Output:

 *   An integer that indicates what kind of number was passed in:

 *     NUM = 3 - a finite value

 *     NAN = 2 - not a number

 *     INF = 1 - an infinite value

 *           0 - zero

 *

 * Description:

 *   This routine returns an integer that indicates the character-

 *   istics of the number that was passed in.

 *

 *****************************************************************/

#include "fdlibm.h"

#include "zmath.h"

#ifndef _DOUBLE_IS_32BITS

int

_DEFUN (numtest, (double),

        double x)

{

  __uint32_t hx, lx;

  int exp;

  EXTRACT_WORDS (hx, lx, x);

  exp = (hx & 0x7ff00000) >> 20;

  /* Check for a zero input. */

  if (x == 0.0)

    {

      return (0);

    }

  /* Check for not a number or infinity. */

  if (exp == 0x7ff)

    {

      if(hx & 0xf0000 || lx)

        return (NAN);

      else

        return (INF);

    }

  /* Otherwise it's a finite value. */

  else

    return (NUM);

}

#endif /* _DOUBLE_IS_32BITS */