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 __scalbl = scalbl
31
32 /*
33 * scalbl(x,n): return x * 2^n by manipulating exponent.
34 */
35
36 #include "libm.h"
37
38 #define n0 0
39
40 long double
scalbl(long double x,long double fn)41 scalbl(long double x, long double fn) {
42 int *py = (int *) &fn, n;
43 long double z;
44
45 if (isnanl(x) || isnanl(fn))
46 return (x * fn);
47
48 /*
49 * fn is inf or NaN
50 */
51 if ((py[n0] & 0x7fff0000) == 0x7fff0000) {
52 if ((py[n0] & 0x80000000) != 0)
53 return (x / (-fn));
54 else
55 return (x * fn);
56 }
57 if (rintl(fn) != fn)
58 return ((fn - fn) / (fn - fn));
59 if (fn > 65000.0L)
60 z = scalbnl(x, 65000);
61 else if (-fn > 65000.0L)
62 z = scalbnl(x, -65000);
63 else {
64 n = (int) fn;
65 z = scalbnl(x, n);
66 }
67 return (z);
68 }
69