/* @(#)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