summaryrefslogtreecommitdiff
path: root/lib/modf.c
blob: 00d5dbc617da519840c9b03f9fcffdc5dac2f99f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
/* Get signed integer and fractional parts of a floating-point number.
   Copyright (C) 2012-2021 Free Software Foundation, Inc.

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

   This file 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 Lesser General Public License for more details.

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

#include <config.h>

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

double
modf (double x, double *iptr)
{
  if (isfinite (x))
    {
      double integer_part = trunc (x);
      *iptr = integer_part;
      return x - integer_part;
    }
  else
    {
      if (isinf (x))
        {
          *iptr = x;
          return 1.0 / x;
        }
      else /* isnand (x) */
        {
          *iptr = x;
          return x;
        }
    }
}