1/* Round long double to integer away from zero.
2 Copyright (C) 1997-2017 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
25
26_Float128
27__roundl (_Float128 x)
28{
29 int32_t j0;
30 u_int64_t i1, i0;
31
32 GET_LDOUBLE_WORDS64 (i0, i1, x);
33 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
34 if (j0 < 48)
35 {
36 if (j0 < 0)
37 {
38 i0 &= 0x8000000000000000ULL;
39 if (j0 == -1)
40 i0 |= 0x3fff000000000000LL;
41 i1 = 0;
42 }
43 else
44 {
45 u_int64_t i = 0x0000ffffffffffffLL >> j0;
46 if (((i0 & i) | i1) == 0)
47 /* X is integral. */
48 return x;
49
50 i0 += 0x0000800000000000LL >> j0;
51 i0 &= ~i;
52 i1 = 0;
53 }
54 }
55 else if (j0 > 111)
56 {
57 if (j0 == 0x4000)
58 /* Inf or NaN. */
59 return x + x;
60 else
61 return x;
62 }
63 else
64 {
65 u_int64_t i = -1ULL >> (j0 - 48);
66 if ((i1 & i) == 0)
67 /* X is integral. */
68 return x;
69
70 u_int64_t j = i1 + (1LL << (111 - j0));
71 if (j < i1)
72 i0 += 1;
73 i1 = j;
74 i1 &= ~i;
75 }
76
77 SET_LDOUBLE_WORDS64 (x, i0, i1);
78 return x;
79}
80weak_alias (__roundl, roundl)
81