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 /* 14 * scalb(x, fn) is provide for 15 * passing various standard test suite. One 16 * should use scalbn() instead. 17 */ 18 19 #include "math.h" 20 #include "math_private.h" 21 22 #ifdef _SCALB_INT 23 double 24 scalb(double x, int fn) 25 { 26 return scalbn(x, fn); 27 } 28 DEF_NONSTD(scalb); 29 30 #else 31 32 double 33 scalb(double x, double fn) 34 { 35 if (isnan(x)||isnan(fn)) return x*fn; 36 if (!isfinite(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 } 45 DEF_NONSTD(scalb); 46 #endif 47