1 /* Round long double value to long long int.
2 Copyright (C) 1997-2022 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 #include <fenv.h>
20 #include <limits.h>
21 #include <math.h>
22
23 #include <math_private.h>
24 #include <libm-alias-ldouble.h>
25
26
27 long long int
__llroundl(long double x)28 __llroundl (long double x)
29 {
30 int32_t j0;
31 uint32_t se, i1, i0;
32 long long int result;
33 int sign;
34
35 GET_LDOUBLE_WORDS (se, i0, i1, x);
36 j0 = (se & 0x7fff) - 0x3fff;
37 sign = (se & 0x8000) != 0 ? -1 : 1;
38
39 if (j0 < 31)
40 {
41 if (j0 < 0)
42 return j0 < -1 ? 0 : sign;
43 else
44 {
45 uint32_t j = i0 + (0x40000000 >> j0);
46 if (j < i0)
47 {
48 j >>= 1;
49 j |= 0x80000000;
50 ++j0;
51 }
52
53 result = j >> (31 - j0);
54 }
55 }
56 else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
57 {
58 if (j0 >= 63)
59 result = (((long long int) i0 << 32) | i1) << (j0 - 63);
60 else
61 {
62 uint32_t j = i1 + (0x80000000 >> (j0 - 31));
63
64 result = (long long int) i0;
65 if (j < i1)
66 ++result;
67
68 if (j0 > 31)
69 {
70 result = (result << (j0 - 31)) | (j >> (63 - j0));
71 #ifdef FE_INVALID
72 if (sign == 1 && result == LLONG_MIN)
73 /* Rounding brought the value out of range. */
74 feraiseexcept (FE_INVALID);
75 #endif
76 }
77 }
78 }
79 else
80 {
81 /* The number is too large. It is left implementation defined
82 what happens. */
83 return (long long int) x;
84 }
85
86 return sign * result;
87 }
88
89 libm_alias_ldouble (__llround, llround)
90