1/* Round __float128 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, write to the Free
19 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
20 02111-1307 USA. */
21
22#include "quadmath-imp.h"
23
24__float128
25roundq (__float128 x)
26{
27 int32_t j0;
28 uint64_t i1, i0;
29
30 GET_FLT128_WORDS64 (i0, i1, x);
31 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
32 if (j0 < 48)
33 {
34 if (j0 < 0)
35 {
36 i0 &= 0x8000000000000000ULL;
37 if (j0 == -1)
38 i0 |= 0x3fff000000000000LL;
39 i1 = 0;
40 }
41 else
42 {
43 uint64_t i = 0x0000ffffffffffffLL >> j0;
44 if (((i0 & i) | i1) == 0)
45 /* X is integral. */
46 return x;
47 i0 += 0x0000800000000000LL >> j0;
48 i0 &= ~i;
49 i1 = 0;
50 }
51 }
52 else if (j0 > 111)
53 {
54 if (j0 == 0x4000)
55 /* Inf or NaN. */
56 return x + x;
57 else
58 return x;
59 }
60 else
61 {
62 uint64_t i = -1ULL >> (j0 - 48);
63 if ((i1 & i) == 0)
64 /* X is integral. */
65 return x;
66
67 uint64_t j = i1 + (1LL << (111 - j0));
68 if (j < i1)
69 i0 += 1;
70 i1 = j;
71 i1 &= ~i;
72 }
73
74 SET_FLT128_WORDS64 (x, i0, i1);
75 return x;
76}
77