1 | /* Round argument to nearest integral value according to current rounding |
2 | direction. |
3 | Copyright (C) 1997-2024 Free Software Foundation, Inc. |
4 | This file is part of the GNU C Library. |
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 <math.h> |
21 | #include <math_private.h> |
22 | #include <libm-alias-double.h> |
23 | #include "mathimpl.h" |
24 | |
25 | long long int |
26 | __llrint (double x) |
27 | { |
28 | int32_t e; |
29 | uint32_t h, l, s; |
30 | long long int result; |
31 | |
32 | x = __m81_u(__rint) (mathop_x: x); |
33 | |
34 | /* We could use __fixxfdi from libgcc, but here we can take advantage of |
35 | the known floating point format. */ |
36 | EXTRACT_WORDS (h, l, x); |
37 | |
38 | e = ((h >> 20) & 0x7ff) - 0x3ff; |
39 | if (e < 0) |
40 | return 0; |
41 | s = h; |
42 | h &= 0xfffff; |
43 | h |= 0x100000; |
44 | |
45 | if (e < 63) |
46 | { |
47 | if (e > 52) |
48 | { |
49 | h <<= e - 52; |
50 | h |= l >> (84 - e); |
51 | l <<= e - 52; |
52 | result = ((long long int) h << 32) | l; |
53 | } |
54 | else if (e > 20) |
55 | { |
56 | l >>= 52 - e; |
57 | l |= h << (e - 20); |
58 | h >>= 52 - e; |
59 | result = ((long long int) h << 32) | l; |
60 | } |
61 | else |
62 | result = h >> (20 - e); |
63 | if (s & 0x80000000) |
64 | result = -result; |
65 | } |
66 | else |
67 | /* The number is too large or not finite. The standard leaves it |
68 | undefined what to return when the number is too large to fit in a |
69 | `long long int'. */ |
70 | result = -1LL; |
71 | |
72 | return result; |
73 | } |
74 | |
75 | libm_alias_double (__llrint, llrint) |
76 | |