1  /* Base 10 logarithmic function.
       2     Copyright (C) 2012-2023 Free Software Foundation, Inc.
       3  
       4     This file is free software: you can redistribute it and/or modify
       5     it under the terms of the GNU Lesser General Public License as
       6     published by the Free Software Foundation, either version 3 of the
       7     License, or (at your option) any later version.
       8  
       9     This file is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public License
      15     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      16  
      17  #include <config.h>
      18  
      19  /* Specification.  */
      20  #include <math.h>
      21  
      22  double
      23  log10 (double x)
      24  #undef log10
      25  {
      26    if (x <= 0.0)
      27      {
      28        /* Work around the OSF/1 5.1 bug.  */
      29        if (x == 0.0)
      30          /* Return -Infinity.  */
      31          return -1.0 / 0.0;
      32        /* Work around the NetBSD 5.1, Solaris 11.0 bug.  */
      33        else /* x < 0.0 */
      34          /* Return NaN.  */
      35          return 0.0 / 0.0;
      36      }
      37    return log10 (x);
      38  }