Retro68/gcc/libquadmath/quadmath-rounding-mode.h
2014-09-21 19:33:12 +02:00

75 lines
1.8 KiB
C

/* GCC Quad-Precision Math Library
Copyright (C) 2012 Free Software Foundation, Inc.
This file is part of the libquadmath library.
Libquadmath is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
Libquadmath 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with libquadmath; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
Boston, MA 02110-1301, USA. */
#ifndef QUADMATH_ROUNDING_MODE_H
#define QUADMATH_ROUNDING_MODE_H
#include <stdbool.h>
#if defined(HAVE_FENV_H)
# include <fenv.h>
#endif /* HAVE_FENV_H */
static inline int
get_rounding_mode (void)
{
#if defined(HAVE_FENV_H) && (defined(FE_DOWNWARD) || defined(FE_TONEAREST) \
|| defined(FE_TOWARDZERO) || defined(FE_UPWARD))
return fegetround ();
#else
return 0;
#endif
}
static inline bool
round_away (bool negative, bool last_digit_odd, bool half_bit, bool more_bits,
int mode)
{
switch (mode)
{
#ifdef FE_DOWNWARD
case FE_DOWNWARD:
return negative && (half_bit || more_bits);
#endif
#ifdef FE_DOWNWARD
case FE_TONEAREST:
return half_bit && (last_digit_odd || more_bits);
#endif
#ifdef FE_TOWARDZERO
case FE_TOWARDZERO:
return false;
#endif
#ifdef FE_UPWARD
case FE_UPWARD:
return !negative && (half_bit || more_bits);
#endif
default:
return false;
}
}
#endif /* QUADMATH_ROUNDING_MODE_H */