#include "mathl.h"
-/* Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov> */
+/* Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov>
+
+ 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 2, 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; see the file COPYING.
+ If not, write to the Free Software Foundation,
+ 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* log(1+x) = x - .5 x^2 + x^3 l(x)
-.0078125 <= x <= +.0078125
long double
logl(long double x)
{
- long double z, y, w, u, t;
+ long double z, y, w;
+ long double u, t;
unsigned int m;
int k, e;
/* log(0) = -infinity. */
if (x == 0.0L)
- return -0.5L / 0.0L;
-
+ {
+ return -0.5L / ZERO;
+ }
/* log ( x < 0 ) = NaN */
if (x < 0.0L)
- return (x - x) / (x - x);
-
+ {
+ return (x - x) / ZERO;
+ }
/* log (infinity or NaN) */
if (x + x == x || x != x)
- return x + x;
+ {
+ return x + x;
+ }
/* Extract exponent and reduce domain to 0.703125 <= u < 1.40625 */
x = frexpl(x, &e);
/* On this interval the table is not used due to cancellation error. */
if ((x <= 1.0078125L) && (x >= 0.9921875L))
{
+ z = x - 1.0L;
k = 64;
t = 1.0L;
- z = x - 1.0L;
}
else
{
- k = floorl((x - 0.5L) * 128.0L);
+ k = floorl ((x - 0.5L) * 128.0L);
t = 0.5L + k / 128.0L;
z = (x - t) / t;
}