1/* Return the least floating-point number greater than X.
2 Copyright (C) 2016-2018 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#include <float.h>
20#include <math.h>
21#include <math_private.h>
22#include <libm-alias-double.h>
23
24/* Return the least floating-point number greater than X. */
25double
26__nextup (double x)
27{
28 int32_t hx, ix;
29 uint32_t lx;
30
31 EXTRACT_WORDS (hx, lx, x);
32 ix = hx & 0x7fffffff;
33
34 if (((ix >= 0x7ff00000) && ((ix - 0x7ff00000) | lx) != 0)) /* x is nan. */
35 return x + x;
36 if ((ix | lx) == 0)
37 return DBL_TRUE_MIN;
38 if (hx >= 0)
39 { /* x > 0. */
40 if (isinf (x))
41 return x;
42 lx += 1;
43 if (lx == 0)
44 hx += 1;
45 }
46 else
47 { /* x < 0. */
48 if (lx == 0)
49 hx -= 1;
50 lx -= 1;
51 }
52 INSERT_WORDS (x, hx, lx);
53 return x;
54}
55
56libm_alias_double (__nextup, nextup)
57