xref: /titanic_51/usr/src/lib/libm/common/R/significandf.c (revision b59c4a48daf5a1863ecac763711b497b2f8321e4)
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 #if defined(ELFOBJ)
31 #pragma weak significandf = __significandf
32 #endif
33 
34 #include "libm.h"
35 
36 float
37 significandf(float x) {
38 	int ix = *(int *) &x & ~0x80000000;
39 
40 	if (ix == 0 || ix >= 0x7f800000)	/* 0/+-Inf/NaN */
41 #if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
42 		return (ix > 0x7f800000 ? x * x : x);
43 #else
44 		return (x + x);
45 #endif
46 	else
47 		return (scalbnf(x, -ilogbf(x)));
48 }
49