Improve the accuracy of tgamma (BZ #26983)

[thirdparty/glibc.git] / math / w_exp_compat.c

/* Copyright (C) 2011-2021 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.

   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_private.h>
#include <math-svid-compat.h>
#include <libm-alias-double.h>

#if LIBM_SVID_COMPAT && (SHLIB_COMPAT (libm, GLIBC_2_0, GLIBC_2_29) \
			 || defined NO_LONG_DOUBLE \
			 || defined LONG_DOUBLE_COMPAT)
/* wrapper exp */
double
__exp_compat (double x)
{
  double z = __ieee754_exp (x);
  if (__builtin_expect (!isfinite (z) || z == 0, 0)
      && isfinite (x) && _LIB_VERSION != _IEEE_)
    return __kernel_standard (x, x, 6 + !!signbit (x));

  return z;
}
# if SHLIB_COMPAT (libm, GLIBC_2_0, GLIBC_2_29)
compat_symbol (libm, __exp_compat, exp, GLIBC_2_0);
# endif
# ifdef NO_LONG_DOUBLE
weak_alias (__exp_compat, expl)
# endif
# ifdef LONG_DOUBLE_COMPAT
/* Work around gas bug "multiple versions for symbol".  */
weak_alias (__exp_compat, __exp_compat_alias)

LONG_DOUBLE_COMPAT_CHOOSE_libm_expl (
  compat_symbol (libm, __exp_compat_alias, expl, FIRST_VERSION_libm_expl), );
# endif
#endif