xref: /illumos-gate/usr/src/lib/libm/common/R/hypotf.c (revision ddc0e0b53c661f6e439e3b7072b3ef353eadb4af)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
24  */
25 /*
26  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #pragma weak __hypotf = hypotf
31 
32 #include "libm.h"
33 
34 float
hypotf(float x,float y)35 hypotf(float x, float y) {
36 	double dx, dy;
37 	float w;
38 	int ix, iy;
39 
40 	ix = (*(int *) &x) & 0x7fffffff;
41 	iy = (*(int *) &y) & 0x7fffffff;
42 	if (ix >= 0x7f800000) {
43 		if (ix == 0x7f800000)
44 			*(int *) &w = x == y ? iy : ix;	/* w = |x| = inf */
45 		else if (iy == 0x7f800000)
46 			*(int *) &w = x == y ? ix : iy;	/* w = |y| = inf */
47 		else
48 			w = fabsf(x) * fabsf(y);	/* + -> * for Cheetah */
49 	} else if (iy >= 0x7f800000) {
50 		if (iy == 0x7f800000)
51 			*(int *) &w = x == y ? ix : iy;	/* w = |y| = inf */
52 		else
53 			w = fabsf(x) * fabsf(y);	/* + -> * for Cheetah */
54 	} else if (ix == 0)
55 		*(int *) &w = iy;	/* w = |y|  */
56 	else if (iy == 0)
57 		*(int *) &w = ix;	/* w = |x|  */
58 	else {
59 		dx = (double) x;
60 		dy = (double) y;
61 		w = (float) sqrt(dx * dx + dy * dy);
62 	}
63 	return (w);
64 }
65