1/* Return the least floating-point number greater than X.
2 Copyright (C) 2016 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
22/* Return the least floating-point number greater than X. */
23double
24__nextup (double x)
25{
26 int32_t hx, ix;
27 u_int32_t lx;
28
29 EXTRACT_WORDS (hx, lx, x);
30 ix = hx & 0x7fffffff;
31
32 if (((ix >= 0x7ff00000) && ((ix - 0x7ff00000) | lx) != 0)) /* x is nan. */
33 return x + x;
34 if ((ix | lx) == 0)
35 return DBL_TRUE_MIN;
36 if (hx >= 0)
37 { /* x > 0. */
38 if (isinf (x))
39 return x;
40 lx += 1;
41 if (lx == 0)
42 hx += 1;
43 }
44 else
45 { /* x < 0. */
46 if (lx == 0)
47 hx -= 1;
48 lx -= 1;
49 }
50 INSERT_WORDS (x, hx, lx);
51 return x;
52}
53
54weak_alias (__nextup, nextup)
55#ifdef NO_LONG_DOUBLE
56strong_alias (__nextup, __nextupl)
57weak_alias (__nextup, nextupl)
58#endif
59