1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2007 AT&T Knowledge Ventures * 5 * and is licensed under the * 6 * Common Public License, Version 1.0 * 7 * by AT&T Knowledge Ventures * 8 * * 9 * A copy of the License is available at * 10 * http://www.opensource.org/licenses/cpl1.0.txt * 11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 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 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