1  /* GCC Quad-Precision Math Library
       2     Copyright (C) 2012 Free Software Foundation, Inc.
       3  
       4  This file is part of the libquadmath library.
       5  Libquadmath is free software; you can redistribute it and/or
       6  modify it under the terms of the GNU Library General Public
       7  License as published by the Free Software Foundation; either
       8  version 2 of the License, or (at your option) any later version.
       9  
      10  Libquadmath is distributed in the hope that it will be useful,
      11  but WITHOUT ANY WARRANTY; without even the implied warranty of
      12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13  Library General Public License for more details.
      14  
      15  You should have received a copy of the GNU Library General Public
      16  License along with libquadmath; see the file COPYING.LIB.  If
      17  not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
      18  Boston, MA 02110-1301, USA.  */
      19  
      20  
      21  #ifndef QUADMATH_ROUNDING_MODE_H
      22  #define QUADMATH_ROUNDING_MODE_H
      23  
      24  #include <stdbool.h>
      25  
      26  
      27  #if defined(HAVE_FENV_H)
      28  #  include <fenv.h>
      29  #endif /* HAVE_FENV_H */
      30  
      31  static inline int
      32  get_rounding_mode (void)
      33  {
      34  #if defined(HAVE_FENV_H) && (defined(FE_DOWNWARD) || defined(FE_TONEAREST) \
      35  			     || defined(FE_TOWARDZERO) || defined(FE_UPWARD))
      36    return fegetround ();
      37  #else
      38    return 0;
      39  #endif
      40  }
      41  
      42  static inline bool
      43  round_away (bool negative, bool last_digit_odd, bool half_bit, bool more_bits,
      44              int mode)
      45  {
      46    switch (mode)
      47      {
      48  #ifdef FE_DOWNWARD
      49      case FE_DOWNWARD:
      50        return negative && (half_bit || more_bits);
      51  #endif
      52  
      53  #ifdef FE_DOWNWARD
      54      case FE_TONEAREST:
      55        return half_bit && (last_digit_odd || more_bits);
      56  #endif
      57  
      58  #ifdef FE_TOWARDZERO
      59      case FE_TOWARDZERO:
      60        return false;
      61  #endif
      62  
      63  
      64  #ifdef FE_UPWARD
      65      case FE_UPWARD:
      66        return !negative && (half_bit || more_bits);
      67  #endif
      68  
      69      default:
      70        return false;
      71      }
      72  }
      73  
      74  #endif /* QUADMATH_ROUNDING_MODE_H  */