1 /* Copyright (C) 2000-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library. If not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #define NO_MATH_REDIRECT
19 #include <math.h>
20 #include <math_ldbl_opt.h>
21 #include <libm-alias-double.h>
22
23
24 double
__rint(double x)25 __rint (double x)
26 {
27 if (isnan (x))
28 return x + x;
29
30 if (isless (fabs (x), 9007199254740992.0)) /* 1 << DBL_MANT_DIG */
31 {
32 double tmp1, new_x;
33 __asm ("cvttq/svid %2,%1\n\t"
34 "cvtqt/d %1,%0\n\t"
35 : "=f"(new_x), "=&f"(tmp1)
36 : "f"(x));
37
38 /* rint(-0.1) == -0, and in general we'll always have the same
39 sign as our input. */
40 x = copysign(new_x, x);
41 }
42 return x;
43 }
44
45 libm_alias_double (__rint, rint)
46