sfdlen.c revision 1
2N/A/***********************************************************************
2N/A* *
2N/A* This software is part of the ast package *
2N/A* Copyright (c) 1985-2011 AT&T Intellectual Property *
2N/A* and is licensed under the *
2N/A* Common Public License, Version 1.0 *
2N/A* by AT&T Intellectual Property *
2N/A* *
2N/A* A copy of the License is available at *
2N/A* http://www.opensource.org/licenses/cpl1.0.txt *
2N/A* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
2N/A* *
2N/A* Information and Software Systems Research *
2N/A* AT&T Research *
2N/A* Florham Park NJ *
2N/A* *
2N/A* Glenn Fowler <gsf@research.att.com> *
2N/A* David Korn <dgk@research.att.com> *
2N/A* Phong Vo <kpv@research.att.com> *
2N/A* *
2N/A***********************************************************************/
2N/A#include "sfhdr.h"
2N/A
2N/A/* Return the length of a double value if coded in a portable format
2N/A**
2N/A** Written by Kiem-Phong Vo
2N/A*/
2N/A
2N/A#if __STD_C
2N/Aint _sfdlen(Sfdouble_t v)
2N/A#else
2N/Aint _sfdlen(v)
2N/ASfdouble_t v;
2N/A#endif
2N/A{
2N/A#define N_ARRAY (16*sizeof(Sfdouble_t))
2N/A reg int n, w;
2N/A Sfdouble_t x;
2N/A int exp;
2N/A
2N/A if(v < 0)
2N/A v = -v;
2N/A
2N/A /* make the magnitude of v < 1 */
2N/A if(v != 0.)
2N/A v = frexpl(v,&exp);
2N/A else exp = 0;
2N/A
2N/A for(w = 1; w <= N_ARRAY; ++w)
2N/A { /* get 2^SF_PRECIS precision at a time */
2N/A n = (int)(x = ldexpl(v,SF_PRECIS));
2N/A v = x-n;
2N/A if(v <= 0.)
2N/A break;
2N/A }
2N/A
2N/A return 1 + sfulen(exp) + w;
2N/A}
2N/A