xref: /titanic_51/usr/src/lib/libm/common/m9x/fmin.c (revision 1ec68d336ba97cd53f46053ac10401d16014d075)
1*25c28e83SPiotr Jasiukajtis /*
2*25c28e83SPiotr Jasiukajtis  * CDDL HEADER START
3*25c28e83SPiotr Jasiukajtis  *
4*25c28e83SPiotr Jasiukajtis  * The contents of this file are subject to the terms of the
5*25c28e83SPiotr Jasiukajtis  * Common Development and Distribution License (the "License").
6*25c28e83SPiotr Jasiukajtis  * You may not use this file except in compliance with the License.
7*25c28e83SPiotr Jasiukajtis  *
8*25c28e83SPiotr Jasiukajtis  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9*25c28e83SPiotr Jasiukajtis  * or http://www.opensolaris.org/os/licensing.
10*25c28e83SPiotr Jasiukajtis  * See the License for the specific language governing permissions
11*25c28e83SPiotr Jasiukajtis  * and limitations under the License.
12*25c28e83SPiotr Jasiukajtis  *
13*25c28e83SPiotr Jasiukajtis  * When distributing Covered Code, include this CDDL HEADER in each
14*25c28e83SPiotr Jasiukajtis  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15*25c28e83SPiotr Jasiukajtis  * If applicable, add the following below this CDDL HEADER, with the
16*25c28e83SPiotr Jasiukajtis  * fields enclosed by brackets "[]" replaced with your own identifying
17*25c28e83SPiotr Jasiukajtis  * information: Portions Copyright [yyyy] [name of copyright owner]
18*25c28e83SPiotr Jasiukajtis  *
19*25c28e83SPiotr Jasiukajtis  * CDDL HEADER END
20*25c28e83SPiotr Jasiukajtis  */
21*25c28e83SPiotr Jasiukajtis 
22*25c28e83SPiotr Jasiukajtis /*
23*25c28e83SPiotr Jasiukajtis  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
24*25c28e83SPiotr Jasiukajtis  */
25*25c28e83SPiotr Jasiukajtis /*
26*25c28e83SPiotr Jasiukajtis  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
27*25c28e83SPiotr Jasiukajtis  * Use is subject to license terms.
28*25c28e83SPiotr Jasiukajtis  */
29*25c28e83SPiotr Jasiukajtis 
30*25c28e83SPiotr Jasiukajtis #pragma weak fmin = __fmin
31*25c28e83SPiotr Jasiukajtis 
32*25c28e83SPiotr Jasiukajtis /*
33*25c28e83SPiotr Jasiukajtis  * fmin(x,y) returns the smaller of x and y.  If just one of the
34*25c28e83SPiotr Jasiukajtis  * arguments is NaN, fmin returns the other argument.  If both
35*25c28e83SPiotr Jasiukajtis  * arguments are NaN, fmin returns NaN.
36*25c28e83SPiotr Jasiukajtis  *
37*25c28e83SPiotr Jasiukajtis  * See fmaxf.c for a discussion of implementation trade-offs.
38*25c28e83SPiotr Jasiukajtis  */
39*25c28e83SPiotr Jasiukajtis 
40*25c28e83SPiotr Jasiukajtis #include "libm.h"	/* for islessequal macro */
41*25c28e83SPiotr Jasiukajtis 
42*25c28e83SPiotr Jasiukajtis #include "fenv_inlines.h"
43*25c28e83SPiotr Jasiukajtis #include <stdio.h>
44*25c28e83SPiotr Jasiukajtis #include <sys/isa_defs.h>
45*25c28e83SPiotr Jasiukajtis 
46*25c28e83SPiotr Jasiukajtis double
47*25c28e83SPiotr Jasiukajtis __fmin(double x, double y) {
48*25c28e83SPiotr Jasiukajtis 	union {
49*25c28e83SPiotr Jasiukajtis 		unsigned i[2];
50*25c28e83SPiotr Jasiukajtis 		double d;
51*25c28e83SPiotr Jasiukajtis 	} xx, yy;
52*25c28e83SPiotr Jasiukajtis 	unsigned s;
53*25c28e83SPiotr Jasiukajtis 
54*25c28e83SPiotr Jasiukajtis 	/* if y is nan, replace it by x */
55*25c28e83SPiotr Jasiukajtis 	if (y != y)
56*25c28e83SPiotr Jasiukajtis 		y = x;
57*25c28e83SPiotr Jasiukajtis 
58*25c28e83SPiotr Jasiukajtis 	/* if x is nan, replace it by y */
59*25c28e83SPiotr Jasiukajtis 	if (x != x)
60*25c28e83SPiotr Jasiukajtis 		x = y;
61*25c28e83SPiotr Jasiukajtis 
62*25c28e83SPiotr Jasiukajtis 	/* At this point, x and y are either both numeric, or both NaN */
63*25c28e83SPiotr Jasiukajtis 	if (!isnan(x) && !islessequal(x, y))
64*25c28e83SPiotr Jasiukajtis 		x = y;
65*25c28e83SPiotr Jasiukajtis 
66*25c28e83SPiotr Jasiukajtis 	/*
67*25c28e83SPiotr Jasiukajtis 	 * set the sign of the result if either x or y has its sign set
68*25c28e83SPiotr Jasiukajtis 	 */
69*25c28e83SPiotr Jasiukajtis 	xx.d = x;
70*25c28e83SPiotr Jasiukajtis 	yy.d = y;
71*25c28e83SPiotr Jasiukajtis #if defined(_BIG_ENDIAN)
72*25c28e83SPiotr Jasiukajtis 	s = (xx.i[0] | yy.i[0]) & 0x80000000;
73*25c28e83SPiotr Jasiukajtis 	xx.i[0] |= s;
74*25c28e83SPiotr Jasiukajtis #else
75*25c28e83SPiotr Jasiukajtis 	s = (xx.i[1] | yy.i[1]) & 0x80000000;
76*25c28e83SPiotr Jasiukajtis 	xx.i[1] |= s;
77*25c28e83SPiotr Jasiukajtis #endif
78*25c28e83SPiotr Jasiukajtis 
79*25c28e83SPiotr Jasiukajtis 	return (xx.d);
80*25c28e83SPiotr Jasiukajtis }
81