1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                 Eclipse Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *          http://www.eclipse.org/org/documents/epl-v10.html           *
11 *         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 #include	"sfhdr.h"
23 
24 /*	Return the length of a double value if coded in a portable format
25 **
26 **	Written by Kiem-Phong Vo
27 */
28 
29 #if __STD_C
_sfdlen(Sfdouble_t v)30 int _sfdlen(Sfdouble_t v)
31 #else
32 int _sfdlen(v)
33 Sfdouble_t	v;
34 #endif
35 {
36 #define N_ARRAY		(16*sizeof(Sfdouble_t))
37 	reg int		n, w;
38 	Sfdouble_t	x;
39 	int		exp;
40 
41 	if(v < 0)
42 		v = -v;
43 
44 	/* make the magnitude of v < 1 */
45 	if(v != 0.)
46 		v = frexpl(v,&exp);
47 	else	exp = 0;
48 
49 	for(w = 1; w <= N_ARRAY; ++w)
50 	{	/* get 2^SF_PRECIS precision at a time */
51 		n = (int)(x = ldexpl(v,SF_PRECIS));
52 		v = x-n;
53 		if(v <= 0.)
54 			break;
55 	}
56 
57 	return 1 + sfulen(exp) + w;
58 }
59