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 __FBSDID("$FreeBSD$"); 16 17 /* 18 * __ieee754_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 __ieee754_scalb(double x, int fn) 29 #else 30 double 31 __ieee754_scalb(double x, double fn) 32 #endif 33 { 34 #ifdef _SCALB_INT 35 return scalbn(x,fn); 36 #else 37 if (isnan(x)||isnan(fn)) return x*fn; 38 if (!finite(fn)) { 39 if(fn>0.0) return x*fn; 40 else return x/(-fn); 41 } 42 if (rint(fn)!=fn) return (fn-fn)/(fn-fn); 43 if ( fn > 65000.0) return scalbn(x, 65000); 44 if (-fn > 65000.0) return scalbn(x,-65000); 45 return scalbn(x,(int)fn); 46 #endif 47 } 48
