math/w_exp_template.c

   1 /* Wrapper to set errno for exp.
   2    Copyright (C) 2017-2018 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 /* Only build wrappers from the templates for the types that define the macro
  20    below.  This macro is set in math-type-macros-<type>.h in sysdeps/generic
  21    for each floating-point type.  */
  22 #if __USE_WRAPPER_TEMPLATE
  23
  24 # include <errno.h>
  25 # include <fenv.h>
  26 # include <math.h>
  27 # include <math_private.h>
  28
  29 /* Provide an additional macro expansion for hidden_def.  */
  30 #define hidden_def_x(name) hidden_def (name)
  31
  32 FLOAT
  33 M_DECL_FUNC (__exp) (FLOAT x)
  34 {
  35   FLOAT z = M_SUF (__ieee754_exp) (x);
  36   if (__glibc_unlikely (!isfinite (z) || z == 0) && isfinite (x))
  37     /* Overflow or underflow.  */
  38     __set_errno (ERANGE);
  39   return z;
  40 }
  41 hidden_def_x (M_SUF (__exp))
  42 declare_mgen_alias (__exp, exp)
  43
  44 #endif /* __USE_WRAPPER_TEMPLATE.  */