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 fmax = __fmax
31*25c28e83SPiotr Jasiukajtis
32*25c28e83SPiotr Jasiukajtis /*
33*25c28e83SPiotr Jasiukajtis * fmax(x,y) returns the larger of x and y. If just one of the
34*25c28e83SPiotr Jasiukajtis * arguments is NaN, fmax returns the other argument. If both
35*25c28e83SPiotr Jasiukajtis * arguments are NaN, fmax 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 isgreaterequal macro */
41*25c28e83SPiotr Jasiukajtis #include <fenv.h>
42*25c28e83SPiotr Jasiukajtis
43*25c28e83SPiotr Jasiukajtis double
__fmax(double x,double y)44*25c28e83SPiotr Jasiukajtis __fmax(double x, double y) {
45*25c28e83SPiotr Jasiukajtis union {
46*25c28e83SPiotr Jasiukajtis unsigned i[2];
47*25c28e83SPiotr Jasiukajtis double d;
48*25c28e83SPiotr Jasiukajtis } xx, yy;
49*25c28e83SPiotr Jasiukajtis unsigned s;
50*25c28e83SPiotr Jasiukajtis
51*25c28e83SPiotr Jasiukajtis /* if y is nan, replace it by x */
52*25c28e83SPiotr Jasiukajtis if (y != y)
53*25c28e83SPiotr Jasiukajtis y = x;
54*25c28e83SPiotr Jasiukajtis
55*25c28e83SPiotr Jasiukajtis /* if x is nan, replace it by y */
56*25c28e83SPiotr Jasiukajtis if (x != x)
57*25c28e83SPiotr Jasiukajtis x = y;
58*25c28e83SPiotr Jasiukajtis
59*25c28e83SPiotr Jasiukajtis /* At this point, x and y are either both numeric, or both NaN */
60*25c28e83SPiotr Jasiukajtis if (!isnan(x) && !isgreaterequal(x, y))
61*25c28e83SPiotr Jasiukajtis x = y;
62*25c28e83SPiotr Jasiukajtis
63*25c28e83SPiotr Jasiukajtis /*
64*25c28e83SPiotr Jasiukajtis * clear the sign of the result if either x or y has its sign clear
65*25c28e83SPiotr Jasiukajtis */
66*25c28e83SPiotr Jasiukajtis xx.d = x;
67*25c28e83SPiotr Jasiukajtis yy.d = y;
68*25c28e83SPiotr Jasiukajtis #if defined(__sparc)
69*25c28e83SPiotr Jasiukajtis s = ~(xx.i[0] & yy.i[0]) & 0x80000000;
70*25c28e83SPiotr Jasiukajtis xx.i[0] &= ~s;
71*25c28e83SPiotr Jasiukajtis #elif defined(__x86)
72*25c28e83SPiotr Jasiukajtis s = ~(xx.i[1] & yy.i[1]) & 0x80000000;
73*25c28e83SPiotr Jasiukajtis xx.i[1] &= ~s;
74*25c28e83SPiotr Jasiukajtis #else
75*25c28e83SPiotr Jasiukajtis #error Unknown architecture
76*25c28e83SPiotr Jasiukajtis #endif
77*25c28e83SPiotr Jasiukajtis
78*25c28e83SPiotr Jasiukajtis return (xx.d);
79*25c28e83SPiotr Jasiukajtis }
80