1 /*
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <math.h>
30
31 #include "fpmath.h"
32
33 long double
fmaximum_magl(long double x,long double y)34 fmaximum_magl(long double x, long double y)
35 {
36 union IEEEl2bits u[2];
37
38 u[0].e = x;
39 mask_nbit_l(u[0]);
40 u[1].e = y;
41 mask_nbit_l(u[1]);
42
43 /* Handle NaN according to ISO/IEC 60559. NaN argument -> NaN return */
44 if (isnan(x) || isnan(y))
45 return (NAN);
46
47 long double ax = fabsl(x);
48 long double ay = fabsl(y);
49
50 if (ay > ax)
51 return (y);
52 if (ax > ay)
53 return (x);
54
55 /* If magnitudes are equal, we break the tie with the sign */
56 if (u[0].bits.sign != u[1].bits.sign)
57 return (u[0].bits.sign ? y : x);
58
59 return (x);
60 }
61
62