1 /*-
2 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/lib/msun/src/s_frexpl.c,v 1.1 2005/03/07 04:54:51 das Exp $
27 */
28
29
30 #if LDBL_MAX_EXP != 0x4000
31 #error "Unsupported long double format"
32 #endif
33
34 long double
frexpl(long double x,int * ex)35 frexpl(long double x, int *ex)
36 {
37 union IEEEl2bits u;
38
39 u.e = x;
40 switch (u.bits.exp) {
41 case 0: /* 0 or subnormal */
42 if ((u.bits.manl | u.bits.manh) == 0) {
43 *ex = 0;
44 } else {
45 u.e *= 0x1.0p514L;
46 *ex = u.bits.exp - 0x4200;
47 u.bits.exp = 0x3ffe;
48 }
49 break;
50 case 0x7fff: /* infinity or NaN; value of *ex is unspecified */
51 return x + x;
52 default: /* normal */
53 *ex = u.bits.exp - 0x3ffe;
54 u.bits.exp = 0x3ffe;
55 break;
56 }
57 return (u.e);
58 }
59
