/* Round to long int long double floating-point values.

   IBM extended format long double version.

   Copyright (C) 2006-2018 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 <math.h>

#include <fenv.h>

#include <math_private.h>

#include <math_ldbl_opt.h>

#include <float.h>

#include <ieee754.h>

long

__lrintl (long double x)

{

  double xh, xl;

  long res, hi, lo;

  int save_round;

  ldbl_unpack (x, &xh, &xl);

  /* Limit the range of values handled by the conversion to long.

     We do this because we aren't sure whether that conversion properly

     raises FE_INVALID.  */

  if (

#if __LONG_MAX__ == 2147483647

      __builtin_expect

      ((__builtin_fabs (xh) <= (double) __LONG_MAX__ + 2), 1)

#else

      __builtin_expect

      ((__builtin_fabs (xh) <= -(double) (-__LONG_MAX__ - 1)), 1)

#endif

#if !defined (FE_INVALID)

      || 1

#endif

    )

    {

      save_round = fegetround ();

#if __LONG_MAX__ == 2147483647

      long long llhi = (long long) xh;

      if (llhi != (long) llhi)

	hi = llhi < 0 ? -__LONG_MAX__ - 1 : __LONG_MAX__;

      else

	hi = llhi;

      xh -= hi;

#else

      if (__glibc_unlikely ((xh == -(double) (-__LONG_MAX__ - 1))))

	{

	  /* When XH is 9223372036854775808.0, converting to long long will

	     overflow, resulting in an invalid operation.  However, XL might

	     be negative and of sufficient magnitude that the overall long

	     double is in fact in range.  Avoid raising an exception.  In any

	     case we need to convert this value specially, because

	     the converted value is not exactly represented as a double

	     thus subtracting HI from XH suffers rounding error.  */

	  hi = __LONG_MAX__;

	  xh = 1.0;

	}

      else

	{

	  hi = (long) xh;

	  xh -= hi;

	}

#endif

      ldbl_canonicalize (&xh, &xl);

      lo = (long) xh;

      /* Peg at max/min values, assuming that the above conversions do so.

         Strictly speaking, we can return anything for values that overflow,

         but this is more useful.  */

      res = (long int) ((unsigned long int) hi + (unsigned long int) lo);

      /* This is just sign(hi) == sign(lo) && sign(res) != sign(hi).  */

      if (__glibc_unlikely (((~(hi ^ lo) & (res ^ hi)) < 0)))

	goto overflow;

      xh -= lo;

      ldbl_canonicalize (&xh, &xl);

      hi = res;

      switch (save_round)

	{

	case FE_TONEAREST:

	  if (fabs (xh) < 0.5

	      || (fabs (xh) == 0.5

		  && ((xh > 0.0 && xl < 0.0)

		      || (xh < 0.0 && xl > 0.0)

		      || (xl == 0.0 && (res & 1) == 0))))

	    return res;

	  if (xh < 0.0)

	    res -= 1UL;

	  else

	    res += 1UL;

	  break;

	case FE_TOWARDZERO:

	  if (res > 0 && (xh < 0.0 || (xh == 0.0 && xl < 0.0)))

	    res -= 1UL;

	  else if (res < 0 && (xh > 0.0 || (xh == 0.0 && xl > 0.0)))

	    res += 1UL;

	  return res;

	  break;

	case FE_UPWARD:

	  if (xh > 0.0 || (xh == 0.0 && xl > 0.0))

	    res += 1UL;

	  break;

	case FE_DOWNWARD:

	  if (xh < 0.0 || (xh == 0.0 && xl < 0.0))

	    res -= 1UL;

	  break;

	}

      if (__glibc_unlikely (((~(hi ^ (res - hi)) & (res ^ hi)) < 0)))

	goto overflow;

      return res;

    }

  else

    {

      if (xh > 0.0)

	hi = __LONG_MAX__;

      else if (xh < 0.0)

	hi = -__LONG_MAX__ - 1;

      else

	/* Nan */

	hi = 0;

    }

overflow:

#ifdef FE_INVALID

  feraiseexcept (FE_INVALID);

#endif

  return hi;

}

long_double_symbol (libm, __lrintl, lrintl);