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 #include <sys/cdefs.h> 15 /* 16 * scalb(x, fn) is provide for 17 * passing various standard test suite. One 18 * should use scalbn() instead. 19 */ 20 21 #include "math.h" 22 #include "math_private.h" 23 24 #ifdef _SCALB_INT 25 double 26 scalb(double x, int fn) 27 #else 28 double 29 scalb(double x, double fn) 30 #endif 31 { 32 #ifdef _SCALB_INT 33 return scalbn(x,fn); 34 #else 35 if (isnan(x)||isnan(fn)) return x*fn; 36 if (!finite(fn)) { 37 if(fn>0.0) return x*fn; 38 else return x/(-fn); 39 } 40 if (rint(fn)!=fn) return (fn-fn)/(fn-fn); 41 if ( fn > 65000.0) return scalbn(x, 65000); 42 if (-fn > 65000.0) return scalbn(x,-65000); 43 return scalbn(x,(int)fn); 44 #endif 45 } 46