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 <math.h>
20#include <math_private.h>
21#include <libm-alias-double.h>
22
23/* Return the least floating-point number greater than X. */
24double
25__nextup (double x)
26{
27 int32_t hx, ix;
28 uint32_t lx;
29
30 EXTRACT_WORDS (hx, lx, x);
31 ix = hx & 0x7fffffff;
32
33 if (((ix >= 0x7ff00000) && ((ix - 0x7ff00000) | lx) != 0)) /* x is nan. */
34 return x + x;
35 if ((ix | lx) == 0)
36 return DBL_TRUE_MIN;
37 if (hx >= 0)
38 { /* x > 0. */
39 if (isinf (x))
40 return x;
41 lx += 1;
42 if (lx == 0)
43 hx += 1;
44 }
45 else
46 { /* x < 0. */
47 if (lx == 0)
48 hx -= 1;
49 lx -= 1;
50 }
51 INSERT_WORDS (x, hx, lx);
52 return x;
53}
54
55libm_alias_double (__nextup, nextup)
56