1570af302Sopenharmony_ci/* origin: FreeBSD /usr/src/lib/msun/src/e_scalb.c */ 2570af302Sopenharmony_ci/* 3570af302Sopenharmony_ci * ==================================================== 4570af302Sopenharmony_ci * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 5570af302Sopenharmony_ci * 6570af302Sopenharmony_ci * Developed at SunSoft, a Sun Microsystems, Inc. business. 7570af302Sopenharmony_ci * Permission to use, copy, modify, and distribute this 8570af302Sopenharmony_ci * software is freely granted, provided that this notice 9570af302Sopenharmony_ci * is preserved. 10570af302Sopenharmony_ci * ==================================================== 11570af302Sopenharmony_ci */ 12570af302Sopenharmony_ci/* 13570af302Sopenharmony_ci * scalb(x, fn) is provide for 14570af302Sopenharmony_ci * passing various standard test suite. One 15570af302Sopenharmony_ci * should use scalbn() instead. 16570af302Sopenharmony_ci */ 17570af302Sopenharmony_ci 18570af302Sopenharmony_ci#define _GNU_SOURCE 19570af302Sopenharmony_ci#include <math.h> 20570af302Sopenharmony_ci 21570af302Sopenharmony_cidouble scalb(double x, double fn) 22570af302Sopenharmony_ci{ 23570af302Sopenharmony_ci if (isnan(x) || isnan(fn)) 24570af302Sopenharmony_ci return x*fn; 25570af302Sopenharmony_ci if (!isfinite(fn)) { 26570af302Sopenharmony_ci if (fn > 0.0) 27570af302Sopenharmony_ci return x*fn; 28570af302Sopenharmony_ci else 29570af302Sopenharmony_ci return x/(-fn); 30570af302Sopenharmony_ci } 31570af302Sopenharmony_ci if (rint(fn) != fn) return (fn-fn)/(fn-fn); 32570af302Sopenharmony_ci if ( fn > 65000.0) return scalbn(x, 65000); 33570af302Sopenharmony_ci if (-fn > 65000.0) return scalbn(x,-65000); 34570af302Sopenharmony_ci return scalbn(x,(int)fn); 35570af302Sopenharmony_ci} 36