xref: /freebsd/lib/msun/src/s_fmaximum_magf.c (revision 4e30c12973c73539bef01be3870a90b6346141e8)
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 <math.h>
30*4e30c129SJesús Blázquez 
31*4e30c129SJesús Blázquez #include "fpmath.h"
32*4e30c129SJesús Blázquez 
33*4e30c129SJesús Blázquez #ifdef USE_BUILTIN_FMAXIMUM_MAGF
34*4e30c129SJesús Blázquez float
fmaximum_magf(float x,float y)35*4e30c129SJesús Blázquez fmaximum_magf(float x, float y)
36*4e30c129SJesús Blázquez {
37*4e30c129SJesús Blázquez 	return (__builtin_fmaximum_magf(x, y));
38*4e30c129SJesús Blázquez }
39*4e30c129SJesús Blázquez #else
40*4e30c129SJesús Blázquez float
fmaximum_magf(float x,float y)41*4e30c129SJesús Blázquez fmaximum_magf(float x, float y)
42*4e30c129SJesús Blázquez {
43*4e30c129SJesús Blázquez 	union IEEEf2bits u[2];
44*4e30c129SJesús Blázquez 
45*4e30c129SJesús Blázquez 	u[0].f = x;
46*4e30c129SJesús Blázquez 	u[1].f = y;
47*4e30c129SJesús Blázquez 
48*4e30c129SJesús Blázquez 	/* Handle NaN according to ISO/IEC 60559. NaN argument -> NaN return */
49*4e30c129SJesús Blázquez 	if ((u[0].bits.exp == 255 && u[0].bits.man != 0) ||
50*4e30c129SJesús Blázquez 	    (u[1].bits.exp == 255 && u[1].bits.man != 0))
51*4e30c129SJesús Blázquez 		return (NAN);
52*4e30c129SJesús Blázquez 
53*4e30c129SJesús Blázquez 	float ax = fabsf(x);
54*4e30c129SJesús Blázquez 	float ay = fabsf(y);
55*4e30c129SJesús Blázquez 
56*4e30c129SJesús Blázquez 	if (ay > ax)
57*4e30c129SJesús Blázquez 		return (y);
58*4e30c129SJesús Blázquez 	if (ax > ay)
59*4e30c129SJesús Blázquez 		return (x);
60*4e30c129SJesús Blázquez 
61*4e30c129SJesús Blázquez 	/* If magnitudes are equal, we break the tie with the sign */
62*4e30c129SJesús Blázquez 	if (u[0].bits.sign != u[1].bits.sign)
63*4e30c129SJesús Blázquez 		return (u[u[0].bits.sign].f);
64*4e30c129SJesús Blázquez 
65*4e30c129SJesús Blázquez 	return (x);
66*4e30c129SJesús Blázquez }
67*4e30c129SJesús Blázquez #endif
68*4e30c129SJesús Blázquez 
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