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. */ |
24 | double |
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 | |
55 | libm_alias_double (__nextup, nextup) |
56 | |