diff options
Diffstat (limited to 'sysdeps/generic/log10.c')
-rw-r--r-- | sysdeps/generic/log10.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/sysdeps/generic/log10.c b/sysdeps/generic/log10.c new file mode 100644 index 0000000000..df52d542be --- /dev/null +++ b/sysdeps/generic/log10.c @@ -0,0 +1,37 @@ +/* Copyright (C) 1991 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <ansidecl.h> +#include <errno.h> +#include <math.h> + +#ifndef LN10 +#define LN10 log(10.0) +#endif + +/* Return the base-ten logarithm of X. */ +double +DEFUN(log10, (x), double x) +{ + static double ln10 = 0.0; + + if (ln10 == 0.0) + ln10 = LN10; + + return log(x) / ln10; +} |