/*

 * ====================================================

 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.

 *

 * Developed at SunPro, a Sun Microsystems, Inc. business.

 * Permission to use, copy, modify, and distribute this

 * software is freely granted, provided that this notice

 * is preserved.

 * ====================================================

 */

/*

 * modf(double x, double *iptr)

 * return fraction part of x, and return x's integral part in *iptr.

 * Method:

 *	Bit twiddling.

 *

 * Exception:

 *	No exception.

 */

#include <math.h>

#include <math_private.h>

#include <libm-alias-double.h>

static const double one = 1.0;

double

__modf (double x, double *iptr)

{

  int32_t i0, i1, j0;

  uint32_t i;

  EXTRACT_WORDS (i0, i1, x);

  j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;    /* exponent of x */

  if (j0 < 20)                          /* integer part in high x */

    {

      if (j0 < 0)                       /* |x|<1 */

	{

	  INSERT_WORDS (*iptr, i0 & 0x80000000, 0);     /* *iptr = +-0 */

	  return x;

	}

      else

	{

	  i = (0x000fffff) >> j0;

	  if (((i0 & i) | i1) == 0)             /* x is integral */

	    {

	      *iptr = x;

	      INSERT_WORDS (x, i0 & 0x80000000, 0);     /* return +-0 */

	      return x;

	    }

	  else

	    {

	      INSERT_WORDS (*iptr, i0 & (~i), 0);

	      return x - *iptr;

	    }

	}

    }

  else if (__glibc_unlikely (j0 > 51))              /* no fraction part */

    {

      *iptr = x * one;

      /* We must handle NaNs separately.  */

      if (j0 == 0x400 && ((i0 & 0xfffff) | i1))

	return x * one;

      INSERT_WORDS (x, i0 & 0x80000000, 0);     /* return +-0 */

      return x;

    }

  else                                  /* fraction part in low x */

    {

      i = ((uint32_t) (0xffffffff)) >> (j0 - 20);

      if ((i1 & i) == 0)                /* x is integral */

	{

	  *iptr = x;

	  INSERT_WORDS (x, i0 & 0x80000000, 0);         /* return +-0 */

	  return x;

	}

      else

	{

	  INSERT_WORDS (*iptr, i0, i1 & (~i));

	  return x - *iptr;

	}

    }

}

#ifndef __modf

libm_alias_double (__modf, modf)

#endif