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 and
5 Jakub Jelinek <jj@ultra.linux.cz>, 1999.
6
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public
9 License as published by the Free Software Foundation; either
10 version 2.1 of the License, or (at your option) any later version.
11
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
16
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, see
19 <http://www.gnu.org/licenses/>. */
20
21#include <math.h>
22
23#include <math_private.h>
24#include <libm-alias-ldouble.h>
25
26
27_Float128
28__roundl (_Float128 x)
29{
30 int32_t j0;
31 uint64_t i1, i0;
32
33 GET_LDOUBLE_WORDS64 (i0, i1, x);
34 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
35 if (j0 < 48)
36 {
37 if (j0 < 0)
38 {
39 i0 &= 0x8000000000000000ULL;
40 if (j0 == -1)
41 i0 |= 0x3fff000000000000LL;
42 i1 = 0;
43 }
44 else
45 {
46 uint64_t i = 0x0000ffffffffffffLL >> j0;
47 if (((i0 & i) | i1) == 0)
48 /* X is integral. */
49 return x;
50
51 i0 += 0x0000800000000000LL >> j0;
52 i0 &= ~i;
53 i1 = 0;
54 }
55 }
56 else if (j0 > 111)
57 {
58 if (j0 == 0x4000)
59 /* Inf or NaN. */
60 return x + x;
61 else
62 return x;
63 }
64 else
65 {
66 uint64_t i = -1ULL >> (j0 - 48);
67 if ((i1 & i) == 0)
68 /* X is integral. */
69 return x;
70
71 uint64_t j = i1 + (1LL << (111 - j0));
72 if (j < i1)
73 i0 += 1;
74 i1 = j;
75 i1 &= ~i;
76 }
77
78 SET_LDOUBLE_WORDS64 (x, i0, i1);
79 return x;
80}
81libm_alias_ldouble (__round, round)
82