kc3-lang/libquadmath/math/llroundq.c

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• Hash : 4f659ab9
  Author : Thomas de Grivel
  Date : 2025-11-02T19:33:45
  

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• math/llroundq.c

• /* Round long double value to long long int.
     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 and
  		  Jakub Jelinek <jj@ultra.linux.cz>, 1999.
  
     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 "quadmath-imp.h"
  
  long long int
  llroundq (__float128 x)
  {
    int64_t j0;
    uint64_t i1, i0;
    long long int result;
    int sign;
  
    GET_FLT128_WORDS64 (i0, i1, x);
    j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
    sign = (i0 & 0x8000000000000000ULL) != 0 ? -1 : 1;
    i0 &= 0x0000ffffffffffffLL;
    i0 |= 0x0001000000000000LL;
  
    if (j0 < 48)
      {
        if (j0 < 0)
  	return j0 < -1 ? 0 : sign;
        else
  	{
  	  i0 += 0x0000800000000000LL >> j0;
  	  result = i0 >> (48 - j0);
  	}
      }
    else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
      {
        if (j0 >= 112)
  	result = ((long long int) i0 << (j0 - 48)) | (i1 << (j0 - 112));
        else
  	{
  	  uint64_t j = i1 + (0x8000000000000000ULL >> (j0 - 48));
  	  if (j < i1)
  	    ++i0;
  
  	  if (j0 == 48)
  	    result = (long long int) i0;
  	  else
  	    {
  	      result = ((long long int) i0 << (j0 - 48)) | (j >> (112 - j0));
  #ifdef FE_INVALID
  	      if (sign == 1 && result == LLONG_MIN)
  		/* Rounding brought the value out of range.  */
  		feraiseexcept (FE_INVALID);
  #endif
  	    }
  	}
      }
    else
      {
        /* The number is too large.  Unless it rounds to LLONG_MIN,
  	 FE_INVALID must be raised and the return value is
  	 unspecified.  */
  #ifdef FE_INVALID
        if (FIX_FLT128_LLONG_CONVERT_OVERFLOW
  	  && !(sign == -1 && x > (__float128) LLONG_MIN - 0.5Q))
  	{
  	  feraiseexcept (FE_INVALID);
  	  return sign == 1 ? LLONG_MAX : LLONG_MIN;
  	}
        else if (!FIX_FLT128_LLONG_CONVERT_OVERFLOW
  	       && x <= (__float128) LLONG_MIN - 0.5Q)
  	{
  	  /* If truncation produces LLONG_MIN, the cast will not raise
  	     the exception, but may raise "inexact".  */
  	  feraiseexcept (FE_INVALID);
  	  return LLONG_MIN;
  	}
  #endif
        return (long long int) x;
      }
  
    return sign * result;
  }
  

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