xref: /freebsd/lib/msun/src/s_fmin.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
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 <float.h>
30 #include <math.h>
31 
32 #include "fpmath.h"
33 
34 #ifdef USE_BUILTIN_FMIN
35 double
36 fmin(double x, double y)
37 {
38 	return (__builtin_fmin(x, y));
39 }
40 #else
41 double
42 fmin(double x, double y)
43 {
44 	union IEEEd2bits u[2];
45 
46 	u[0].d = x;
47 	u[1].d = y;
48 
49 	/* Check for NaNs to avoid raising spurious exceptions. */
50 	if (u[0].bits.exp == 2047 && (u[0].bits.manh | u[0].bits.manl) != 0)
51 		return (y);
52 	if (u[1].bits.exp == 2047 && (u[1].bits.manh | u[1].bits.manl) != 0)
53 		return (x);
54 
55 	/* Handle comparisons of signed zeroes. */
56 	if (u[0].bits.sign != u[1].bits.sign)
57 		return (u[u[1].bits.sign].d);
58 
59 	return (x < y ? x : y);
60 }
61 #endif
62 
63 #if (LDBL_MANT_DIG == 53)
64 __weak_reference(fmin, fminl);
65 #endif
66