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63551311 | 1 | /* Round long double to integer away from zero. |
2b778ceb | 2 | Copyright (C) 1997-2021 Free Software Foundation, Inc. |
63551311 UD |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
63551311 UD |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
41bdb6e2 | 14 | Lesser General Public License for more details. |
63551311 | 15 | |
41bdb6e2 | 16 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 | 17 | License along with the GNU C Library; if not, see |
5a82c748 | 18 | <https://www.gnu.org/licenses/>. */ |
63551311 | 19 | |
9755bc46 | 20 | #define NO_MATH_REDIRECT |
63551311 UD |
21 | #include <math.h> |
22 | ||
1ed0291c | 23 | #include <math_private.h> |
86f9568a | 24 | #include <libm-alias-ldouble.h> |
63551311 UD |
25 | |
26 | ||
63551311 UD |
27 | long double |
28 | __roundl (long double x) | |
29 | { | |
30 | int32_t j0; | |
24ab7723 | 31 | uint32_t se, i1, i0; |
63551311 UD |
32 | |
33 | GET_LDOUBLE_WORDS (se, i0, i1, x); | |
34 | j0 = (se & 0x7fff) - 0x3fff; | |
35 | if (j0 < 31) | |
36 | { | |
37 | if (j0 < 0) | |
38 | { | |
d7826aa1 UD |
39 | se &= 0x8000; |
40 | i0 = i1 = 0; | |
41 | if (j0 == -1) | |
63551311 | 42 | { |
d7826aa1 UD |
43 | se |= 0x3fff; |
44 | i0 = 0x80000000; | |
63551311 UD |
45 | } |
46 | } | |
47 | else | |
48 | { | |
24ab7723 | 49 | uint32_t i = 0x7fffffff >> j0; |
63551311 UD |
50 | if (((i0 & i) | i1) == 0) |
51 | /* X is integral. */ | |
52 | return x; | |
d7826aa1 | 53 | |
24ab7723 | 54 | uint32_t j = i0 + (0x40000000 >> j0); |
d7826aa1 UD |
55 | if (j < i0) |
56 | se += 1; | |
57 | i0 = (j & ~i) | 0x80000000; | |
58 | i1 = 0; | |
63551311 UD |
59 | } |
60 | } | |
61 | else if (j0 > 62) | |
62 | { | |
63 | if (j0 == 0x4000) | |
64 | /* Inf or NaN. */ | |
65 | return x + x; | |
66 | else | |
67 | return x; | |
68 | } | |
69 | else | |
70 | { | |
24ab7723 | 71 | uint32_t i = 0xffffffff >> (j0 - 31); |
63551311 UD |
72 | if ((i1 & i) == 0) |
73 | /* X is integral. */ | |
74 | return x; | |
75 | ||
24ab7723 | 76 | uint32_t j = i1 + (1 << (62 - j0)); |
d7826aa1 | 77 | if (j < i1) |
63551311 | 78 | { |
24ab7723 | 79 | uint32_t k = i0 + 1; |
d7826aa1 | 80 | if (k < i0) |
63551311 | 81 | { |
d7826aa1 UD |
82 | se += 1; |
83 | k |= 0x80000000; | |
63551311 | 84 | } |
d7826aa1 | 85 | i0 = k; |
63551311 | 86 | } |
d7826aa1 | 87 | i1 = j; |
63551311 UD |
88 | i1 &= ~i; |
89 | } | |
90 | ||
91 | SET_LDOUBLE_WORDS (x, se, i0, i1); | |
92 | return x; | |
93 | } | |
86f9568a | 94 | libm_alias_ldouble (__round, round) |