math/w_log_template.c

   1 /* Wrapper to set errno for log.
   2    Copyright (C) 2017 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 <fenv.h>
  25 # include <math.h>
  26 # include <math_private.h>
  27
  28 FLOAT
  29 M_DECL_FUNC (__log) (FLOAT x)
  30 {
  31   if (__glibc_unlikely (islessequal (x, M_LIT (0.0))))
  32     {
  33       if (x == 0)
  34         /* Pole error: log(0).  */
  35         __set_errno (ERANGE);
  36       else
  37         /* Domain error: log(<0).  */
  38         __set_errno (EDOM);
  39     }
  40   return M_SUF (__ieee754_log) (x);
  41 }
  42 declare_mgen_alias (__log, log)
  43
  44 #endif /* __USE_WRAPPER_TEMPLATE.  */