1 /* @(#)e_scalb.c 5.1 93/09/24 */ 2 /* 3 * ==================================================== 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 5 * 6 * Developed at SunPro, a Sun Microsystems, Inc. business. 7 * Permission to use, copy, modify, and distribute this 8 * software is freely granted, provided that this notice 9 * is preserved. 10 * ==================================================== 11 */ 12 13 #if defined(LIBM_SCCS) && !defined(lint) 14 static char rcsid[] = "$NetBSD: e_scalb.c,v 1.6 1995/05/10 20:46:09 jtc Exp $"; 15 #endif 16 17 /* 18 * scalb(x, fn) is provide for 19 * passing various standard test suite. One 20 * should use scalbn() instead. 21 */ 22 23 #include "math.h" 24 #include "math_private.h" 25 26 #ifdef _SCALB_INT 27 double 28 scalb(double x, int fn) 29 { 30 return scalbn(x, fn); 31 } 32 33 #else 34 35 double 36 scalb(double x, double fn) 37 { 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 } 48 #endif 49