1/* Round long double to integer away from zero.
2 Copyright (C) 1997-2021 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#define NO_MATH_REDIRECT
21#include <math.h>
22
23#include <math_private.h>
24#include <libm-alias-ldouble.h>
25
26
27long double
28__roundl (long double x)
29{
30 int32_t j0;
31 uint32_t se, i1, i0;
32
33 GET_LDOUBLE_WORDS (se, i0, i1, x);
34 j0 = (se & 0x7fff) - 0x3fff;
35 if (j0 < 31)
36 {
37 if (j0 < 0)
38 {
39 se &= 0x8000;
40 i0 = i1 = 0;
41 if (j0 == -1)
42 {
43 se |= 0x3fff;
44 i0 = 0x80000000;
45 }
46 }
47 else
48 {
49 uint32_t i = 0x7fffffff >> j0;
50 if (((i0 & i) | i1) == 0)
51 /* X is integral. */
52 return x;
53
54 uint32_t j = i0 + (0x40000000 >> j0);
55 if (j < i0)
56 se += 1;
57 i0 = (j & ~i) | 0x80000000;
58 i1 = 0;
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 {
71 uint32_t i = 0xffffffff >> (j0 - 31);
72 if ((i1 & i) == 0)
73 /* X is integral. */
74 return x;
75
76 uint32_t j = i1 + (1 << (62 - j0));
77 if (j < i1)
78 {
79 uint32_t k = i0 + 1;
80 if (k < i0)
81 {
82 se += 1;
83 k |= 0x80000000;
84 }
85 i0 = k;
86 }
87 i1 = j;
88 i1 &= ~i;
89 }
90
91 SET_LDOUBLE_WORDS (x, se, i0, i1);
92 return x;
93}
94libm_alias_ldouble (__round, round)
95