xref: /freebsd/lib/msun/src/s_fminimum_num.c (revision 4e30c12973c73539bef01be3870a90b6346141e8)
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 #include <stdbool.h>
33 
34 #include "fpmath.h"
35 
36 #ifdef USE_BUILTIN_FMINIMUM_NUM
37 double
fminimum_num(double x,double y)38 fminimum_num(double x, double y)
39 {
40 	return (__builtin_fminimum_num(x, y));
41 }
42 #else
43 double
fminimum_num(double x,double y)44 fminimum_num(double x, double y)
45 {
46 	union IEEEd2bits u[2];
47 	bool nan_x, nan_y;
48 
49 	u[0].d = x;
50 	u[1].d = y;
51 
52 	nan_x = u[0].bits.exp == 2047 && (u[0].bits.manh | u[0].bits.manl) != 0;
53 	nan_y = u[1].bits.exp == 2047 && (u[1].bits.manh | u[1].bits.manl) != 0;
54 
55 	if (nan_x || nan_y) {
56 		/* These ternary conditionals force (x+y), so that sNaN's raise exceptions */
57 		if (nan_x && nan_y)
58 			return (x + y);
59 		if (nan_x)
60 			return ((x + y) != 0.0 ? y : y);
61 		return ((x + y) != 0.0 ? x : x);
62 	}
63 
64 	/* Handle comparisons of signed zeroes. */
65 	if (u[0].bits.sign != u[1].bits.sign)
66 		return (u[u[1].bits.sign].d);
67 
68 	return (x < y ? x : y);
69 }
70 #endif
71 
72 #if (LDBL_MANT_DIG == 53)
73 __weak_reference(fminimum_num, fminimum_numl);
74 #endif
75 
76 
77