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 frexpf = __frexpf
31
32 #include "libm.h"
33
34 float
__frexpf(float x,int * exp)35 __frexpf(float x, int *exp) {
36 union {
37 unsigned i;
38 float f;
39 } xx;
40 unsigned hx;
41 int e;
42
43 xx.f = x;
44 hx = xx.i & ~0x80000000;
45
46 if (hx >= 0x7f800000) { /* x is infinite or NaN */
47 *exp = 0;
48 return (x);
49 }
50
51 e = 0;
52 if (hx < 0x00800000) { /* x is subnormal or zero */
53 if (hx == 0) {
54 *exp = 0;
55 return (x);
56 }
57
58 /* normalize x by regarding it as an integer */
59 xx.f = (int) xx.i < 0 ? -(int) hx : (int) hx;
60 hx = xx.i & ~0x80000000;
61 e = -149;
62 }
63
64 /* now xx.f is normal */
65 xx.i = (xx.i & ~0x7f800000) | 0x3f000000;
66 *exp = e + (hx >> 23) - 0x7e;
67 return (xx.f);
68 }
69