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 <math.h>
31 #include <stdbool.h>
32
33 #include "fpmath.h"
34
35 #ifdef USE_BUILTIN_FMINIMUM_MAG_NUMF
36 float
fminimum_mag_numf(float x,float y)37 fminimum_mag_numf(float x, float y)
38 {
39 return (__builtin_fminimum_mag_numf(x, y));
40 }
41 #else
42 float
fminimum_mag_numf(float x,float y)43 fminimum_mag_numf(float x, float y)
44 {
45 union IEEEf2bits u[2];
46 bool nan_x, nan_y;
47
48 u[0].f = x;
49 u[1].f = y;
50
51 nan_x = isnan(x);
52 nan_y = isnan(y);
53
54 if (nan_x || nan_y) {
55 /* If both are NaN, adding returns qNaN */
56 if (nan_x && nan_y)
57 return (x + y);
58
59 /* force_except makes sure sNaN's raise exceptions */
60 volatile float force_except = x + y;
61 force_except;
62
63 if (nan_x)
64 return (y);
65 else
66 return (x);
67 }
68
69 float ax = fabsf(x);
70 float ay = fabsf(y);
71
72 if (ay < ax)
73 return (y);
74 if (ax < ay)
75 return (x);
76
77 /* If magnitudes are equal, we break the tie with the sign */
78 if (u[0].bits.sign != u[1].bits.sign)
79 return (u[u[1].bits.sign].f);
80
81 return (x);
82 }
83 #endif
84
85
86