POK
/home/jaouen/pok_official/pok/trunk/libpok/libm/e_scalb.c
00001 /*
00002  *                               POK header
00003  * 
00004  * The following file is a part of the POK project. Any modification should
00005  * made according to the POK licence. You CANNOT use this file or a part of
00006  * this file is this part of a file for your own project
00007  *
00008  * For more information on the POK licence, please see our LICENCE FILE
00009  *
00010  * Please follow the coding guidelines described in doc/CODING_GUIDELINES
00011  *
00012  *                                      Copyright (c) 2007-2009 POK team 
00013  *
00014  * Created by julien on Fri Jan 30 14:41:34 2009 
00015  */
00016 
00017 /* @(#)e_scalb.c 5.1 93/09/24 */
00018 /*
00019  * ====================================================
00020  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
00021  *
00022  * Developed at SunPro, a Sun Microsystems, Inc. business.
00023  * Permission to use, copy, modify, and distribute this
00024  * software is freely granted, provided that this notice
00025  * is preserved.
00026  * ====================================================
00027  */
00028 
00029 /*
00030  * __ieee754_scalb(x, fn) is provide for
00031  * passing various standard test suite. One
00032  * should use scalbn() instead.
00033  */
00034 
00035 #ifdef POK_NEEDS_LIBMATH
00036 
00037 #include <libm.h>
00038 #include "math_private.h"
00039 
00040 #ifdef _SCALB_INT
00041 double
00042 __ieee754_scalb(double x, int fn)
00043 #else
00044 double
00045 __ieee754_scalb(double x, double fn)
00046 #endif
00047 {
00048 #ifdef _SCALB_INT
00049         return scalbn(x,fn);
00050 #else
00051         if (isnan(x)||isnan(fn)) return x*fn;
00052         if (!finite(fn)) {
00053             if(fn>0.0) return x*fn;
00054             else       return x/(-fn);
00055         }
00056         if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
00057         if ( fn > 65000.0) return scalbn(x, 65000);
00058         if (-fn > 65000.0) return scalbn(x,-65000);
00059         return scalbn(x,(int)fn);
00060 #endif
00061 }
00062 #endif
00063