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
34float
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