source: trunk/sys/libm/w_exp.c @ 95

/* @(#)w_exp.c 5.1 93/09/24 */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice 
 * is preserved.
 * ====================================================
 */

/* 
 * wrapper exp(x)
 */

#include <libm/fdlibm.h>

#ifdef __STDC__
static const double
#else
static double
#endif
o_threshold=  7.09782712893383973096e+02,  /* 0x40862E42, 0xFEFA39EF */
u_threshold= -7.45133219101941108420e+02;  /* 0xc0874910, 0xD52D3051 */

#ifdef __STDC__
        double exp(double x)            /* wrapper exp */
#else
        double exp(x)                   /* wrapper exp */
        double x;
#endif
{
#ifdef _IEEE_LIBM
        return __ieee754_exp(x);
#else
        double z;
        z = __ieee754_exp(x);
        if(_LIB_VERSION == _IEEE_) return z;
        if(finite(x)) {
            if(x>o_threshold)
                return __kernel_standard(x,x,6); /* exp overflow */
            else if(x<u_threshold)
                return __kernel_standard(x,x,7); /* exp underflow */
        } 
        return z;
#endif
}