s_fmax.c revision 331722 
1/*-
2 * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/11/lib/msun/src/s_fmax.c 331722 2018-03-29 02:50:57Z eadler $");
29
30#include <float.h>
31#include <math.h>
32
33#include "fpmath.h"
34
35double
36fmax(double x, double y)
37{
38	union IEEEd2bits u[2];
39
40	u[0].d = x;
41	u[1].d = y;
42
43	/* Check for NaNs to avoid raising spurious exceptions. */
44	if (u[0].bits.exp == 2047 && (u[0].bits.manh | u[0].bits.manl) != 0)
45		return (y);
46	if (u[1].bits.exp == 2047 && (u[1].bits.manh | u[1].bits.manl) != 0)
47		return (x);
48
49	/* Handle comparisons of signed zeroes. */
50	if (u[0].bits.sign != u[1].bits.sign)
51		return (u[u[0].bits.sign].d);
52
53	return (x > y ? x : y);
54}
55
56#if (LDBL_MANT_DIG == 53)
57__weak_reference(fmax, fmaxl);
58#endif
59