1/* Round long double to integer away from zero.
2 Copyright (C) 1997-2018 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 <http://www.gnu.org/licenses/>. */
19
20#include <math.h>
21
22#include <math_private.h>
23#include <libm-alias-ldouble.h>
24
25
26long double
27__roundl (long double x)
28{
29 int32_t j0;
30 uint32_t se, i1, i0;
31
32 GET_LDOUBLE_WORDS (se, i0, i1, x);
33 j0 = (se & 0x7fff) - 0x3fff;
34 if (j0 < 31)
35 {
36 if (j0 < 0)
37 {
38 se &= 0x8000;
39 i0 = i1 = 0;
40 if (j0 == -1)
41 {
42 se |= 0x3fff;
43 i0 = 0x80000000;
44 }
45 }
46 else
47 {
48 uint32_t i = 0x7fffffff >> j0;
49 if (((i0 & i) | i1) == 0)
50 /* X is integral. */
51 return x;
52
53 uint32_t j = i0 + (0x40000000 >> j0);
54 if (j < i0)
55 se += 1;
56 i0 = (j & ~i) | 0x80000000;
57 i1 = 0;
58 }
59 }
60 else if (j0 > 62)
61 {
62 if (j0 == 0x4000)
63 /* Inf or NaN. */
64 return x + x;
65 else
66 return x;
67 }
68 else
69 {
70 uint32_t i = 0xffffffff >> (j0 - 31);
71 if ((i1 & i) == 0)
72 /* X is integral. */
73 return x;
74
75 uint32_t j = i1 + (1 << (62 - j0));
76 if (j < i1)
77 {
78 uint32_t k = i0 + 1;
79 if (k < i0)
80 {
81 se += 1;
82 k |= 0x80000000;
83 }
84 i0 = k;
85 }
86 i1 = j;
87 i1 &= ~i;
88 }
89
90 SET_LDOUBLE_WORDS (x, se, i0, i1);
91 return x;
92}
93libm_alias_ldouble (__round, round)
94