1/*	$OpenBSD: s_frexpl.c,v 1.2 2016/09/12 19:47:02 guenther Exp $	*/
2/*-
3 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD: src/lib/msun/src/s_frexpl.c,v 1.1 2005/03/07 04:54:51 das Exp $
28 */
29
30#include <sys/types.h>
31#include <machine/ieee.h>
32#include <float.h>
33#include <math.h>
34
35#if LDBL_MAX_EXP != 0x4000
36#error "Unsupported long double format"
37#endif
38
39long double
40frexpl(long double x, int *ex)
41{
42	struct ieee_ext *p = (struct ieee_ext *)&x;
43
44	switch (p->ext_exp) {
45	case 0:		/* 0 or subnormal */
46		if ((p->ext_fracl
47#ifdef EXT_FRACLMBITS
48			| p->ext_fraclm
49#endif /* EXT_FRACLMBITS */
50#ifdef EXT_FRACHMBITS
51			| p->ext_frachm
52#endif /* EXT_FRACHMBITS */
53			| p->ext_frach) == 0) {
54			*ex = 0;
55		} else {
56			x *= 0x1.0p514;
57			*ex = p->ext_exp - 0x4200;
58			p->ext_exp = 0x3ffe;
59		}
60		break;
61	case 0x7fff:	/* infinity or NaN; value of *ex is unspecified */
62		break;
63	default:	/* normal */
64		*ex = p->ext_exp - 0x3ffe;
65		p->ext_exp = 0x3ffe;
66		break;
67	}
68
69	return x;
70}
71DEF_STD(frexpl);
72