1 /*
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright © 2022 Keith Packard
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
17 *
18 * 3. Neither the name of the copyright holder nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
29 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
33 * OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 long double
nearbyintl(long double x)37 nearbyintl(long double x)
38 {
39 union IEEEl2bits u;
40 double dh, dl, frac;
41
42 u.e = x;
43 if (u.bits.exp == LDBL_INF_NAN_EXP)
44 return x + x;
45 dh = nearbyint(u.dbits.dh);
46 frac = u.dbits.dh - dh;
47 if (frac != 0.0) {
48 /* Adjust rounding when upper fraction is 0.5 */
49 if (u.dbits.dl > 0 && frac == 0.5)
50 dh += 1.0;
51 else if(u.dbits.dl < 0 && frac == -0.5)
52 dh -= 1.0;
53 dl = 0;
54 } else
55 dl = nearbyint(u.dbits.dl);
56 return (long double) dh + (long double) dl;
57 }
58
59 long double
rintl(long double x)60 rintl(long double x)
61 {
62 long double y = nearbyintl(x);
63 if (x != y)
64 return __math_inexactl(y);
65 return y;
66 }
67
