1 | /* Round long double value to long long int. |
2 | Copyright (C) 1997-2020 Free Software Foundation, Inc. |
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 |
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. |
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 |
14 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <https://www.gnu.org/licenses/>. */ |
19 | |
20 | #include <fenv.h> |
21 | #include <limits.h> |
22 | #include <math.h> |
23 | |
24 | #include <math_private.h> |
25 | #include <libm-alias-ldouble.h> |
26 | |
27 | |
28 | long long int |
29 | __llroundl (long double x) |
30 | { |
31 | int32_t j0; |
32 | uint32_t se, i1, i0; |
33 | long long int result; |
34 | int sign; |
35 | |
36 | GET_LDOUBLE_WORDS (se, i0, i1, x); |
37 | j0 = (se & 0x7fff) - 0x3fff; |
38 | sign = (se & 0x8000) != 0 ? -1 : 1; |
39 | |
40 | if (j0 < 31) |
41 | { |
42 | if (j0 < 0) |
43 | return j0 < -1 ? 0 : sign; |
44 | else |
45 | { |
46 | uint32_t j = i0 + (0x40000000 >> j0); |
47 | if (j < i0) |
48 | { |
49 | j >>= 1; |
50 | j |= 0x80000000; |
51 | ++j0; |
52 | } |
53 | |
54 | result = j >> (31 - j0); |
55 | } |
56 | } |
57 | else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1) |
58 | { |
59 | if (j0 >= 63) |
60 | result = (((long long int) i0 << 32) | i1) << (j0 - 63); |
61 | else |
62 | { |
63 | uint32_t j = i1 + (0x80000000 >> (j0 - 31)); |
64 | |
65 | result = (long long int) i0; |
66 | if (j < i1) |
67 | ++result; |
68 | |
69 | if (j0 > 31) |
70 | { |
71 | result = (result << (j0 - 31)) | (j >> (63 - j0)); |
72 | #ifdef FE_INVALID |
73 | if (sign == 1 && result == LLONG_MIN) |
74 | /* Rounding brought the value out of range. */ |
75 | feraiseexcept (FE_INVALID); |
76 | #endif |
77 | } |
78 | } |
79 | } |
80 | else |
81 | { |
82 | /* The number is too large. It is left implementation defined |
83 | what happens. */ |
84 | return (long long int) x; |
85 | } |
86 | |
87 | return sign * result; |
88 | } |
89 | |
90 | libm_alias_ldouble (__llround, llround) |
91 | |