1  /* Round long double value to long long int.
       2     Copyright (C) 1997-2018 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4     Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and
       5  		  Jakub Jelinek <jj@ultra.linux.cz>, 1999.
       6  
       7     The GNU C Library is free software; you can redistribute it and/or
       8     modify it under the terms of the GNU Lesser General Public
       9     License as published by the Free Software Foundation; either
      10     version 2.1 of the License, or (at your option) any later version.
      11  
      12     The GNU C Library is distributed in the hope that it will be useful,
      13     but WITHOUT ANY WARRANTY; without even the implied warranty of
      14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      15     Lesser General Public License for more details.
      16  
      17     You should have received a copy of the GNU Lesser General Public
      18     License along with the GNU C Library; if not, see
      19     <http://www.gnu.org/licenses/>.  */
      20  
      21  #include "quadmath-imp.h"
      22  
      23  long long int
      24  llroundq (__float128 x)
      25  {
      26    int64_t j0;
      27    uint64_t i1, i0;
      28    long long int result;
      29    int sign;
      30  
      31    GET_FLT128_WORDS64 (i0, i1, x);
      32    j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
      33    sign = (i0 & 0x8000000000000000ULL) != 0 ? -1 : 1;
      34    i0 &= 0x0000ffffffffffffLL;
      35    i0 |= 0x0001000000000000LL;
      36  
      37    if (j0 < 48)
      38      {
      39        if (j0 < 0)
      40  	return j0 < -1 ? 0 : sign;
      41        else
      42  	{
      43  	  i0 += 0x0000800000000000LL >> j0;
      44  	  result = i0 >> (48 - j0);
      45  	}
      46      }
      47    else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
      48      {
      49        if (j0 >= 112)
      50  	result = ((long long int) i0 << (j0 - 48)) | (i1 << (j0 - 112));
      51        else
      52  	{
      53  	  uint64_t j = i1 + (0x8000000000000000ULL >> (j0 - 48));
      54  	  if (j < i1)
      55  	    ++i0;
      56  
      57  	  if (j0 == 48)
      58  	    result = (long long int) i0;
      59  	  else
      60  	    {
      61  	      result = ((long long int) i0 << (j0 - 48)) | (j >> (112 - j0));
      62  #ifdef FE_INVALID
      63  	      if (sign == 1 && result == LLONG_MIN)
      64  		/* Rounding brought the value out of range.  */
      65  		feraiseexcept (FE_INVALID);
      66  #endif
      67  	    }
      68  	}
      69      }
      70    else
      71      {
      72        /* The number is too large.  Unless it rounds to LLONG_MIN,
      73  	 FE_INVALID must be raised and the return value is
      74  	 unspecified.  */
      75  #ifdef FE_INVALID
      76        if (FIX_FLT128_LLONG_CONVERT_OVERFLOW
      77  	  && !(sign == -1 && x > (__float128) LLONG_MIN - 0.5Q))
      78  	{
      79  	  feraiseexcept (FE_INVALID);
      80  	  return sign == 1 ? LLONG_MAX : LLONG_MIN;
      81  	}
      82        else if (!FIX_FLT128_LLONG_CONVERT_OVERFLOW
      83  	       && x <= (__float128) LLONG_MIN - 0.5Q)
      84  	{
      85  	  /* If truncation produces LLONG_MIN, the cast will not raise
      86  	     the exception, but may raise "inexact".  */
      87  	  feraiseexcept (FE_INVALID);
      88  	  return LLONG_MIN;
      89  	}
      90  #endif
      91        return (long long int) x;
      92      }
      93  
      94    return sign * result;
      95  }