xref: /onnv-gate/usr/src/lib/libast/common/sfio/sfdlen.c (revision 12068:08a39a083754)
14887Schin /***********************************************************************
24887Schin *                                                                      *
34887Schin *               This software is part of the ast package               *
4*12068SRoger.Faulkner@Oracle.COM *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
54887Schin *                      and is licensed under the                       *
64887Schin *                  Common Public License, Version 1.0                  *
78462SApril.Chin@Sun.COM *                    by AT&T Intellectual Property                     *
84887Schin *                                                                      *
94887Schin *                A copy of the License is available at                 *
104887Schin *            http://www.opensource.org/licenses/cpl1.0.txt             *
114887Schin *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
124887Schin *                                                                      *
134887Schin *              Information and Software Systems Research               *
144887Schin *                            AT&T Research                             *
154887Schin *                           Florham Park NJ                            *
164887Schin *                                                                      *
174887Schin *                 Glenn Fowler <gsf@research.att.com>                  *
184887Schin *                  David Korn <dgk@research.att.com>                   *
194887Schin *                   Phong Vo <kpv@research.att.com>                    *
204887Schin *                                                                      *
214887Schin ***********************************************************************/
224887Schin #include	"sfhdr.h"
234887Schin 
244887Schin /*	Return the length of a double value if coded in a portable format
254887Schin **
264887Schin **	Written by Kiem-Phong Vo
274887Schin */
284887Schin 
294887Schin #if __STD_C
_sfdlen(Sfdouble_t v)304887Schin int _sfdlen(Sfdouble_t v)
314887Schin #else
324887Schin int _sfdlen(v)
334887Schin Sfdouble_t	v;
344887Schin #endif
354887Schin {
364887Schin #define N_ARRAY		(16*sizeof(Sfdouble_t))
374887Schin 	reg int		n, w;
384887Schin 	Sfdouble_t	x;
394887Schin 	int		exp;
404887Schin 
414887Schin 	if(v < 0)
424887Schin 		v = -v;
434887Schin 
444887Schin 	/* make the magnitude of v < 1 */
454887Schin 	if(v != 0.)
464887Schin 		v = frexpl(v,&exp);
474887Schin 	else	exp = 0;
484887Schin 
494887Schin 	for(w = 1; w <= N_ARRAY; ++w)
504887Schin 	{	/* get 2^SF_PRECIS precision at a time */
514887Schin 		n = (int)(x = ldexpl(v,SF_PRECIS));
524887Schin 		v = x-n;
534887Schin 		if(v <= 0.)
544887Schin 			break;
554887Schin 	}
564887Schin 
574887Schin 	return 1 + sfulen(exp) + w;
584887Schin }
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