1 2 /* @(#)e_scalb.c 1.3 95/01/18 */ 3 /* 4 * ==================================================== 5 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 6 * 7 * Developed at SunSoft, a Sun Microsystems, Inc. business. 8 * Permission to use, copy, modify, and distribute this 9 * software is freely granted, provided that this notice 10 * is preserved. 11 * ==================================================== 12 */ 13 14 #ifndef lint 15 static char rcsid[] = "$FreeBSD: src/lib/msun/src/e_scalb.c,v 1.12 2005/02/04 18:26:06 das Exp $"; 16 #endif 17 18 /* 19 * __ieee754_scalb(x, fn) is provide for 20 * passing various standard test suite. One 21 * should use scalbn() instead. 22 */ 23 24 #include "math.h" 25 #include "math_private.h" 26 27 #ifdef _SCALB_INT 28 double 29 __ieee754_scalb(double x, int fn) 30 #else 31 double 32 __ieee754_scalb(double x, double fn) 33 #endif 34 { 35 #ifdef _SCALB_INT 36 return scalbn(x,fn); 37 #else 38 if (isnan(x)||isnan(fn)) return x*fn; 39 if (!finite(fn)) { 40 if(fn>0.0) return x*fn; 41 else return x/(-fn); 42 } 43 if (rint(fn)!=fn) return (fn-fn)/(fn-fn); 44 if ( fn > 65000.0) return scalbn(x, 65000); 45 if (-fn > 65000.0) return scalbn(x,-65000); 46 return scalbn(x,(int)fn); 47 #endif 48 } 49
