/* @(#)s_ceil.c 5.1 93/09/24 */

/*

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

 * 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.

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

 */

/*

 * ceil(x)

 * Return x rounded toward -inf to integral value

 * Method:

 *	Bit twiddling.

 */

#include <math.h>

#include <math_private.h>

#include <libm-alias-double.h>

double

__ceil (double x)

{

  int64_t i0, i;

  int32_t j0;

  EXTRACT_WORDS64 (i0, x);

  j0 = ((i0 >> 52) & 0x7ff) - 0x3ff;

  if (j0 <= 51)

    {

      if (j0 < 0)

	{

	  /* return 0 * sign(x) if |x| < 1  */

	  if (i0 < 0)

	    i0 = INT64_C (0x8000000000000000);

	  else if (i0 != 0)

	    i0 = INT64_C (0x3ff0000000000000);

	}

      else

	{

	  i = INT64_C (0x000fffffffffffff) >> j0;

	  if ((i0 & i) == 0)

	    return x;			/* x is integral  */

	  if (i0 > 0)

	    i0 += UINT64_C (0x0010000000000000) >> j0;

	  i0 &= ~i;

	}

    }

  else

    {

      if (j0 == 0x400)

	return x + x;			/* inf or NaN  */

      else

	return x;			/* x is integral  */

    }

  INSERT_WORDS64 (x, i0);

  return x;

}

#ifndef __ceil

libm_alias_double (__ceil, ceil)

#endif