1 | /* Round long double to integer away from zero. |
2 | Copyright (C) 1997-2023 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 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #define NO_MATH_REDIRECT |
20 | #include <math.h> |
21 | |
22 | #include <math_private.h> |
23 | #include <libm-alias-ldouble.h> |
24 | |
25 | |
26 | long double |
27 | __roundl (long double x) |
28 | { |
29 | int32_t j0; |
30 | uint32_t se, i1, i0; |
31 | |
32 | GET_LDOUBLE_WORDS (se, i0, i1, x); |
33 | j0 = (se & 0x7fff) - 0x3fff; |
34 | if (j0 < 31) |
35 | { |
36 | if (j0 < 0) |
37 | { |
38 | se &= 0x8000; |
39 | i0 = i1 = 0; |
40 | if (j0 == -1) |
41 | { |
42 | se |= 0x3fff; |
43 | i0 = 0x80000000; |
44 | } |
45 | } |
46 | else |
47 | { |
48 | uint32_t i = 0x7fffffff >> j0; |
49 | if (((i0 & i) | i1) == 0) |
50 | /* X is integral. */ |
51 | return x; |
52 | |
53 | uint32_t j = i0 + (0x40000000 >> j0); |
54 | if (j < i0) |
55 | se += 1; |
56 | i0 = (j & ~i) | 0x80000000; |
57 | i1 = 0; |
58 | } |
59 | } |
60 | else if (j0 > 62) |
61 | { |
62 | if (j0 == 0x4000) |
63 | /* Inf or NaN. */ |
64 | return x + x; |
65 | else |
66 | return x; |
67 | } |
68 | else |
69 | { |
70 | uint32_t i = 0xffffffff >> (j0 - 31); |
71 | if ((i1 & i) == 0) |
72 | /* X is integral. */ |
73 | return x; |
74 | |
75 | uint32_t j = i1 + (1 << (62 - j0)); |
76 | if (j < i1) |
77 | { |
78 | uint32_t k = i0 + 1; |
79 | if (k < i0) |
80 | { |
81 | se += 1; |
82 | k |= 0x80000000; |
83 | } |
84 | i0 = k; |
85 | } |
86 | i1 = j; |
87 | i1 &= ~i; |
88 | } |
89 | |
90 | SET_LDOUBLE_WORDS (x, se, i0, i1); |
91 | return x; |
92 | } |
93 | libm_alias_ldouble (__round, round) |
94 | |