1/* Return positive difference between arguments.
2 Copyright (C) 1997, 2004, 2009 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, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA. */
20
21#include <errno.h>
22#include "quadmath-imp.h"
23
24__float128
25fdimq (__float128 x, __float128 y)
26{
27 int clsx = fpclassifyq (x);
28 int clsy = fpclassifyq (y);
29
30 if (clsx == QUADFP_NAN || clsy == QUADFP_NAN
31 || (y < 0 && clsx == QUADFP_INFINITE && clsy == QUADFP_INFINITE))
32 /* Raise invalid flag. */
33 return x - y;
34
35 if (x <= y)
36 return 0.0Q;
37
38 __float128 r = x - y;
39 if (isinfq (r))
40 errno = ERANGE;
41
42 return r;
43}
44