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 #define NO_MATH_REDIRECT
22
23 #include "quadmath-imp.h"
24
25 __float128
roundq(__float128 x)26 roundq (__float128 x)
27 {
28 int32_t j0;
29 uint64_t i1, i0;
30
31 GET_FLT128_WORDS64 (i0, i1, x);
32 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
33 if (j0 < 48)
34 {
35 if (j0 < 0)
36 {
37 i0 &= 0x8000000000000000ULL;
38 if (j0 == -1)
39 i0 |= 0x3fff000000000000LL;
40 i1 = 0;
41 }
42 else
43 {
44 uint64_t i = 0x0000ffffffffffffLL >> j0;
45 if (((i0 & i) | i1) == 0)
46 /* X is integral. */
47 return x;
48
49 i0 += 0x0000800000000000LL >> j0;
50 i0 &= ~i;
51 i1 = 0;
52 }
53 }
54 else if (j0 > 111)
55 {
56 if (j0 == 0x4000)
57 /* Inf or NaN. */
58 return x + x;
59 else
60 return x;
61 }
62 else
63 {
64 uint64_t i = -1ULL >> (j0 - 48);
65 if ((i1 & i) == 0)
66 /* X is integral. */
67 return x;
68
69 uint64_t j = i1 + (1LL << (111 - j0));
70 if (j < i1)
71 i0 += 1;
72 i1 = j;
73 i1 &= ~i;
74 }
75
76 SET_FLT128_WORDS64 (x, i0, i1);
77 return x;
78 }
79