1/* Return positive difference between arguments.
2 Copyright (C) 1997-2016 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
19
20#include <errno.h>
21#include <math.h>
22
23float
24__fdimf (float x, float y)
25{
26 int clsx = fpclassify (x);
27 int clsy = fpclassify (y);
28
29 if (clsx == FP_NAN || clsy == FP_NAN)
30 /* Raise invalid flag for signaling but not quiet NaN. */
31 return x - y;
32
33 if (x <= y)
34 return 0.0f;
35
36 float r = x - y;
37 if (fpclassify (r) == FP_INFINITE
38 && clsx != FP_INFINITE && clsy != FP_INFINITE)
39 __set_errno (ERANGE);
40
41 return r;
42}
43weak_alias (__fdimf, fdimf)
44