1 /*
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
5 * Copyright (c) 2026 Jesús Blázquez <jesuscblazquez@gmail.com>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <float.h>
31 #include <math.h>
32
33 #include "fpmath.h"
34
35 #ifdef USE_BUILTIN_FMAXIMUM
36 double
fmaximum(double x,double y)37 fmaximum(double x, double y)
38 {
39 return (__builtin_fmaximum(x, y));
40 }
41 #else
42 double
fmaximum(double x,double y)43 fmaximum(double x, double y)
44 {
45 union IEEEd2bits u[2];
46
47 u[0].d = x;
48 u[1].d = y;
49
50 /* Handle NaN according to ISO/IEC 60559. NaN argument -> NaN return */
51 if ((u[0].bits.exp == 2047 && (u[0].bits.manh | u[0].bits.manl) != 0) ||
52 (u[1].bits.exp == 2047 && (u[1].bits.manh | u[1].bits.manl) != 0))
53 return (NAN);
54
55 /* Handle comparisons of signed zeroes. */
56 if (u[0].bits.sign != u[1].bits.sign)
57 return (u[u[0].bits.sign].d);
58
59 return (x > y ? x : y);
60 }
61 #endif
62
63 #if (LDBL_MANT_DIG == 53)
64 __weak_reference(fmaximum, fmaximuml);
65 #endif
66