view lib/log10f.c @ 40086:d6de7c427079

stdopen: modernize and simplify * lib/stdopen.c: Update copyright date Do not include sys/types.h; no longer needed these days. (stdopen): Use C99-style decl in loop. Return int errno value, rather than just a bool. Do not worry about fd mismatches, since the caller cares only if 0, 1, 2 are occupied. * lib/stdopen.h: No need to include <stdbool.h>. * m4/stdopen.m4: Remove. * modules/stdopen: New file.
author Paul Eggert <eggert@cs.ucla.edu>
date Sat, 05 Jan 2019 18:02:32 -0800
parents b06060465f09
children
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/* Base 10 logarithmic function.
   Copyright (C) 2011-2019 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */
#include <math.h>

float
log10f (float x)
#undef log10f
{
#if HAVE_LOG10F
  if (x <= 0.0f)
    {
      /* Work around the OSF/1 5.1 bug.  */
      if (x == 0.0f)
        /* Return -Infinity.  */
        return -1.0f / 0.0f;
      /* Work around the NetBSD 5.1 bug.  */
      else /* x < 0.0 */
        /* Return NaN.  */
        return 0.0f / 0.0f;
    }
  return log10f (x);
#else
  return (float) log10 ((double) x);
#endif
}