1 | /* Round long double to integer away from zero. |
2 | Copyright (C) 1997-2018 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and |
5 | Jakub Jelinek <jj@ultra.linux.cz>, 1999. |
6 | |
7 | The GNU C Library is free software; you can redistribute it and/or |
8 | modify it under the terms of the GNU Lesser General Public |
9 | License as published by the Free Software Foundation; either |
10 | version 2.1 of the License, or (at your option) any later version. |
11 | |
12 | The GNU C Library is distributed in the hope that it will be useful, |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
15 | Lesser General Public License for more details. |
16 | |
17 | You should have received a copy of the GNU Lesser General Public |
18 | License along with the GNU C Library; if not, see |
19 | <http://www.gnu.org/licenses/>. */ |
20 | |
21 | #include <math.h> |
22 | |
23 | #include <math_private.h> |
24 | #include <libm-alias-ldouble.h> |
25 | |
26 | |
27 | _Float128 |
28 | __roundl (_Float128 x) |
29 | { |
30 | int32_t j0; |
31 | uint64_t i1, i0; |
32 | |
33 | GET_LDOUBLE_WORDS64 (i0, i1, x); |
34 | j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; |
35 | if (j0 < 48) |
36 | { |
37 | if (j0 < 0) |
38 | { |
39 | i0 &= 0x8000000000000000ULL; |
40 | if (j0 == -1) |
41 | i0 |= 0x3fff000000000000LL; |
42 | i1 = 0; |
43 | } |
44 | else |
45 | { |
46 | uint64_t i = 0x0000ffffffffffffLL >> j0; |
47 | if (((i0 & i) | i1) == 0) |
48 | /* X is integral. */ |
49 | return x; |
50 | |
51 | i0 += 0x0000800000000000LL >> j0; |
52 | i0 &= ~i; |
53 | i1 = 0; |
54 | } |
55 | } |
56 | else if (j0 > 111) |
57 | { |
58 | if (j0 == 0x4000) |
59 | /* Inf or NaN. */ |
60 | return x + x; |
61 | else |
62 | return x; |
63 | } |
64 | else |
65 | { |
66 | uint64_t i = -1ULL >> (j0 - 48); |
67 | if ((i1 & i) == 0) |
68 | /* X is integral. */ |
69 | return x; |
70 | |
71 | uint64_t j = i1 + (1LL << (111 - j0)); |
72 | if (j < i1) |
73 | i0 += 1; |
74 | i1 = j; |
75 | i1 &= ~i; |
76 | } |
77 | |
78 | SET_LDOUBLE_WORDS64 (x, i0, i1); |
79 | return x; |
80 | } |
81 | libm_alias_ldouble (__round, round) |
82 | |