/* Round to integer type.  ldbl-128 version.

   Copyright (C) 2016-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   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 <errno.h>

#include <fenv.h>

#include <math.h>

#include <math_private.h>

#include <libm-alias-ldouble.h>

#include <stdbool.h>

#include <stdint.h>

#define BIAS 0x3fff

#define MANT_DIG 113

#if UNSIGNED

# define RET_TYPE uintmax_t

#else

# define RET_TYPE intmax_t

#endif

#include <fromfp.h>

RET_TYPE

FUNC (_Float128 x, int round, unsigned int width)

{

  if (width > INTMAX_WIDTH)

    width = INTMAX_WIDTH;

  uint64_t hx, lx;

  GET_LDOUBLE_WORDS64 (hx, lx, x);

  bool negative = (hx & 0x8000000000000000ULL) != 0;

  if (width == 0)

    return fromfp_domain_error (negative, width);

  hx &= 0x7fffffffffffffffULL;

  if ((hx | lx) == 0)

    return 0;

  int exponent = hx >> (MANT_DIG - 1 - 64);

  exponent -= BIAS;

  int max_exponent = fromfp_max_exponent (negative, width);

  if (exponent > max_exponent)

    return fromfp_domain_error (negative, width);

  hx &= ((1ULL << (MANT_DIG - 1 - 64)) - 1);

  hx |= 1ULL << (MANT_DIG - 1 - 64);

  uintmax_t uret;

  bool half_bit, more_bits;

  /* The exponent is at most 63, so we are shifting right by at least

     49 bits.  */

  if (exponent >= -1)

    {

      int shift = MANT_DIG - 1 - exponent;

      if (shift <= 64)

	{

	  uint64_t h = 1ULL << (shift - 1);

	  half_bit = (lx & h) != 0;

	  more_bits = (lx & (h - 1)) != 0;

	  uret = hx << (64 - shift);

	  if (shift != 64)

	    uret |= lx >> shift;

	}

      else

	{

	  uint64_t h = 1ULL << (shift - 1 - 64);

	  half_bit = (hx & h) != 0;

	  more_bits = ((hx & (h - 1)) | lx) != 0;

	  uret = hx >> (shift - 64);

	}

    }

  else

    {

      uret = 0;

      half_bit = false;

      more_bits = true;

    }

  return fromfp_round_and_return (negative, uret, half_bit, more_bits, round,

				  exponent, max_exponent, width);

}