/* Round double to integer away from zero.

   Copyright (C) 1997-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <math.h>

#include <math_private.h>

#include <libm-alias-double.h>

#include <stdint.h>

#include <math-use-builtins.h>

double

__round (double x)

{

#if USE_ROUND_BUILTIN

  return __builtin_round (x);

#else

  /* Use generic implementation.  */

  int64_t i0, j0;

  EXTRACT_WORDS64 (i0, x);

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

  if (__glibc_likely (j0 < 52))

    {

      if (j0 < 0)

	{

	  i0 &= UINT64_C (0x8000000000000000);

	  if (j0 == -1)

	    i0 |= UINT64_C (0x3ff0000000000000);

	}

      else

	{

	  uint64_t i = UINT64_C (0x000fffffffffffff) >> j0;

	  if ((i0 & i) == 0)

	    /* X is integral.  */

	    return x;

	  i0 += UINT64_C (0x0008000000000000) >> j0;

	  i0 &= ~i;

	}

    }

  else

    {

      if (j0 == 0x400)

	/* Inf or NaN.  */

	return x + x;

      else

	return x;

    }

  INSERT_WORDS64 (x, i0);

  return x;

#endif /* ! USE_ROUND_BUILTIN  */

}

libm_alias_double (__round, round)