1/* Round long double to integer away from zero.
2 Copyright (C) 1997-2016 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
19
20#include <math.h>
21
22#include <math_private.h>
23
24
25static const long double huge = 1.0e4930L;
26
27
28long double
29__roundl (long double x)
30{
31 int32_t j0;
32 u_int32_t se, i1, i0;
33
34 GET_LDOUBLE_WORDS (se, i0, i1, x);
35 j0 = (se & 0x7fff) - 0x3fff;
36 if (j0 < 31)
37 {
38 if (j0 < 0)
39 {
40 math_force_eval (huge + x);
41 se &= 0x8000;
42 i0 = i1 = 0;
43 if (j0 == -1)
44 {
45 se |= 0x3fff;
46 i0 = 0x80000000;
47 }
48 }
49 else
50 {
51 u_int32_t i = 0x7fffffff >> j0;
52 if (((i0 & i) | i1) == 0)
53 /* X is integral. */
54 return x;
55
56 /* Raise inexact if x != 0. */
57 math_force_eval (huge + x);
58 u_int32_t j = i0 + (0x40000000 >> j0);
59 if (j < i0)
60 se += 1;
61 i0 = (j & ~i) | 0x80000000;
62 i1 = 0;
63 }
64 }
65 else if (j0 > 62)
66 {
67 if (j0 == 0x4000)
68 /* Inf or NaN. */
69 return x + x;
70 else
71 return x;
72 }
73 else
74 {
75 u_int32_t i = 0xffffffff >> (j0 - 31);
76 if ((i1 & i) == 0)
77 /* X is integral. */
78 return x;
79
80 math_force_eval (huge + x);
81 /* Raise inexact if x != 0. */
82 u_int32_t j = i1 + (1 << (62 - j0));
83 if (j < i1)
84 {
85 u_int32_t k = i0 + 1;
86 if (k < i0)
87 {
88 se += 1;
89 k |= 0x80000000;
90 }
91 i0 = k;
92 }
93 i1 = j;
94 i1 &= ~i;
95 }
96
97 SET_LDOUBLE_WORDS (x, se, i0, i1);
98 return x;
99}
100weak_alias (__roundl, roundl)
101