POK
/home/jaouen/pok_official/pok/trunk/libpok/libm/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 /* @(#)w_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 #ifdef POK_NEEDS_LIBMATH
00030 
00031 /*
00032  * wrapper scalb(double x, double fn) is provide for
00033  * passing various standard test suite. One
00034  * should use scalbn() instead.
00035  */
00036 
00037 #include <libm.h>
00038 #include "math_private.h"
00039 
00040 #include <errno.h>
00041 
00042 #ifdef _SCALB_INT
00043 double
00044 scalb(double x, int fn)         /* wrapper scalb */
00045 #else
00046 double
00047 scalb(double x, double fn)      /* wrapper scalb */
00048 #endif
00049 {
00050 #ifdef _IEEE_LIBM
00051         return __ieee754_scalb(x,fn);
00052 #else
00053         double z;
00054         z = __ieee754_scalb(x,fn);
00055         if(_LIB_VERSION == _IEEE_) return z;
00056         if(!(finite(z)||isnan(z))&&finite(x)) {
00057             return __kernel_standard(x,(double)fn,32); /* scalb overflow */
00058         }
00059         if(z==0.0&&z!=x) {
00060             return __kernel_standard(x,(double)fn,33); /* scalb underflow */
00061         }
00062 #ifndef _SCALB_INT
00063         if(!finite(fn)) errno = POK_ERRNO_ERANGE;
00064 #endif
00065         return z;
00066 #endif
00067 }
00068 
00069 #endif