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 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 <https://www.gnu.org/licenses/>. */
20
21#define NO_MATH_REDIRECT
22#include <math.h>
23
24#include <math_private.h>
25#include <libm-alias-ldouble.h>
26#include <math-use-builtins.h>
27
28
29_Float128
30__roundl (_Float128 x)
31{
32#if USE_ROUNDL_BUILTIN
33 return __builtin_roundl (x);
34#else
35 /* Use generic implementation. */
36 int32_t j0;
37 uint64_t i1, i0;
38
39 GET_LDOUBLE_WORDS64 (i0, i1, x);
40 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
41 if (j0 < 48)
42 {
43 if (j0 < 0)
44 {
45 i0 &= 0x8000000000000000ULL;
46 if (j0 == -1)
47 i0 |= 0x3fff000000000000LL;
48 i1 = 0;
49 }
50 else
51 {
52 uint64_t i = 0x0000ffffffffffffLL >> j0;
53 if (((i0 & i) | i1) == 0)
54 /* X is integral. */
55 return x;
56
57 i0 += 0x0000800000000000LL >> j0;
58 i0 &= ~i;
59 i1 = 0;
60 }
61 }
62 else if (j0 > 111)
63 {
64 if (j0 == 0x4000)
65 /* Inf or NaN. */
66 return x + x;
67 else
68 return x;
69 }
70 else
71 {
72 uint64_t i = -1ULL >> (j0 - 48);
73 if ((i1 & i) == 0)
74 /* X is integral. */
75 return x;
76
77 uint64_t j = i1 + (1LL << (111 - j0));
78 if (j < i1)
79 i0 += 1;
80 i1 = j;
81 i1 &= ~i;
82 }
83
84 SET_LDOUBLE_WORDS64 (x, i0, i1);
85 return x;
86#endif /* ! USE_ROUNDL_BUILTIN */
87}
88libm_alias_ldouble (__round, round)
89