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 /* 15 * __ieee754_scalb(x, fn) is provide for 16 * passing various standard test suite. One 17 * should use ieee_scalbn() instead. 18 */ 19 20 #include "fdlibm.h" 21 22 #ifdef _SCALB_INT 23 #ifdef __STDC__ 24 double __ieee754_scalb(double x, int fn) 25 #else 26 double __ieee754_scalb(x,fn) 27 double x; int fn; 28 #endif 29 #else 30 #ifdef __STDC__ 31 double __ieee754_scalb(double x, double fn) 32 #else 33 double __ieee754_scalb(x,fn) 34 double x, fn; 35 #endif 36 #endif 37 { 38 #ifdef _SCALB_INT 39 return ieee_scalbn(x,fn); 40 #else 41 if (ieee_isnan(x)||ieee_isnan(fn)) return x*fn; 42 if (!ieee_finite(fn)) { 43 if(fn>0.0) return x*fn; 44 else return x/(-fn); 45 } 46 if (ieee_rint(fn)!=fn) return (fn-fn)/(fn-fn); 47 if ( fn > 65000.0) return ieee_scalbn(x, 65000); 48 if (-fn > 65000.0) return ieee_scalbn(x,-65000); 49 return ieee_scalbn(x,(int)fn); 50 #endif 51 } 52
