1*4e30c129SJesús Blázquez /*
2*4e30c129SJesús Blázquez * SPDX-License-Identifier: BSD-2-Clause
3*4e30c129SJesús Blázquez *
4*4e30c129SJesús Blázquez * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
5*4e30c129SJesús Blázquez * All rights reserved.
6*4e30c129SJesús Blázquez *
7*4e30c129SJesús Blázquez * Redistribution and use in source and binary forms, with or without
8*4e30c129SJesús Blázquez * modification, are permitted provided that the following conditions
9*4e30c129SJesús Blázquez * are met:
10*4e30c129SJesús Blázquez * 1. Redistributions of source code must retain the above copyright
11*4e30c129SJesús Blázquez * notice, this list of conditions and the following disclaimer.
12*4e30c129SJesús Blázquez * 2. Redistributions in binary form must reproduce the above copyright
13*4e30c129SJesús Blázquez * notice, this list of conditions and the following disclaimer in the
14*4e30c129SJesús Blázquez * documentation and/or other materials provided with the distribution.
15*4e30c129SJesús Blázquez *
16*4e30c129SJesús Blázquez * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17*4e30c129SJesús Blázquez * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18*4e30c129SJesús Blázquez * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19*4e30c129SJesús Blázquez * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20*4e30c129SJesús Blázquez * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21*4e30c129SJesús Blázquez * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22*4e30c129SJesús Blázquez * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23*4e30c129SJesús Blázquez * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24*4e30c129SJesús Blázquez * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25*4e30c129SJesús Blázquez * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26*4e30c129SJesús Blázquez * SUCH DAMAGE.
27*4e30c129SJesús Blázquez */
28*4e30c129SJesús Blázquez
29*4e30c129SJesús Blázquez #include <float.h>
30*4e30c129SJesús Blázquez #include <math.h>
31*4e30c129SJesús Blázquez
32*4e30c129SJesús Blázquez #include "fpmath.h"
33*4e30c129SJesús Blázquez
34*4e30c129SJesús Blázquez #ifdef USE_BUILTIN_FMAXIMUM_MAG
35*4e30c129SJesús Blázquez double
fmaximum_mag(double x,double y)36*4e30c129SJesús Blázquez fmaximum_mag(double x, double y)
37*4e30c129SJesús Blázquez {
38*4e30c129SJesús Blázquez return (__builtin_fmaximum_mag(x, y));
39*4e30c129SJesús Blázquez }
40*4e30c129SJesús Blázquez #else
41*4e30c129SJesús Blázquez double
fmaximum_mag(double x,double y)42*4e30c129SJesús Blázquez fmaximum_mag(double x, double y)
43*4e30c129SJesús Blázquez {
44*4e30c129SJesús Blázquez union IEEEd2bits u[2];
45*4e30c129SJesús Blázquez
46*4e30c129SJesús Blázquez u[0].d = x;
47*4e30c129SJesús Blázquez u[1].d = y;
48*4e30c129SJesús Blázquez
49*4e30c129SJesús Blázquez /* Handle NaN according to ISO/IEC 60559. NaN argument -> NaN return */
50*4e30c129SJesús Blázquez if ((u[0].bits.exp == 2047 && (u[0].bits.manh | u[0].bits.manl) != 0) ||
51*4e30c129SJesús Blázquez (u[1].bits.exp == 2047 && (u[1].bits.manh | u[1].bits.manl) != 0))
52*4e30c129SJesús Blázquez return (NAN);
53*4e30c129SJesús Blázquez
54*4e30c129SJesús Blázquez double ax = fabs(x);
55*4e30c129SJesús Blázquez double ay = fabs(y);
56*4e30c129SJesús Blázquez
57*4e30c129SJesús Blázquez if (ay > ax)
58*4e30c129SJesús Blázquez return (y);
59*4e30c129SJesús Blázquez if (ax > ay)
60*4e30c129SJesús Blázquez return (x);
61*4e30c129SJesús Blázquez
62*4e30c129SJesús Blázquez /* If magnitudes are equal, we break the tie with the sign */
63*4e30c129SJesús Blázquez if (u[0].bits.sign != u[1].bits.sign)
64*4e30c129SJesús Blázquez return (u[u[0].bits.sign].d);
65*4e30c129SJesús Blázquez
66*4e30c129SJesús Blázquez return (x);
67*4e30c129SJesús Blázquez }
68*4e30c129SJesús Blázquez #endif
69*4e30c129SJesús Blázquez
70*4e30c129SJesús Blázquez #if (LDBL_MANT_DIG == 53)
71*4e30c129SJesús Blázquez __weak_reference(fmaximum_mag, fmaximum_magl);
72*4e30c129SJesús Blázquez #endif
73*4e30c129SJesús Blázquez
74