1/* Round double value to long long int.
2 Copyright (C) 1997-2019 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#define lround __hidden_lround
21#define __lround __hidden___lround
22
23#include <math.h>
24#include <sysdep.h>
25
26#include <math_private.h>
27#include <libm-alias-double.h>
28
29
30long long int
31__llround (double x)
32{
33 int32_t j0;
34 int64_t i0;
35 long long int result;
36 int sign;
37
38 EXTRACT_WORDS64 (i0, x);
39 j0 = ((i0 >> 52) & 0x7ff) - 0x3ff;
40 sign = i0 < 0 ? -1 : 1;
41 i0 &= UINT64_C(0xfffffffffffff);
42 i0 |= UINT64_C(0x10000000000000);
43
44 if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
45 {
46 if (j0 < 0)
47 return j0 < -1 ? 0 : sign;
48 else if (j0 >= 52)
49 result = i0 << (j0 - 52);
50 else
51 {
52 i0 += UINT64_C(0x8000000000000) >> j0;
53
54 result = i0 >> (52 - j0);
55 }
56 }
57 else
58 {
59 /* The number is too large. It is left implementation defined
60 what happens. */
61 return (long long int) x;
62 }
63
64 return sign * result;
65}
66
67libm_alias_double (__llround, llround)
68
69/* long has the same width as long long on LP64 machines, so use an alias. */
70#undef lround
71#undef __lround
72#ifdef _LP64
73strong_alias (__llround, __lround)
74libm_alias_double (__lround, lround)
75#endif
76