glibc/sysdeps/ieee754/ldbl-128/s_f64xsubf128.c

/* Subtract _Float128 values, converting the result to _Float64x.
   Copyright (C) 2018-2021 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
   <https://www.gnu.org/licenses/>.  */

#include <math.h>
#include <math-narrow.h>

/* math_ldbl.h defines _Float128 to long double for this directory,
   but when they are different, this function must be defined with
   _Float128 arguments to avoid defining an alias with an incompatible
   type.  */
#undef _Float128

_Float64x
__f64xsubf128 (_Float128 x, _Float128 y)
{
#if __HAVE_FLOAT64X_LONG_DOUBLE && __HAVE_DISTINCT_FLOAT128
  NARROW_SUB_ROUND_TO_ODD (x, y, _Float64x, union ieee854_long_double, l,
			   mantissa3);
#else
  NARROW_SUB_TRIVIAL (x, y, _Float64x);
#endif
}
libm_alias_float64x_float128 (sub)