__ieee754_exp
t = __ieee754_exp(fabs(x));
if (ix < 0x40862E42) return half*__ieee754_exp(fabs(x));
w = __ieee754_exp(half*fabs(x));
if (ix < 0x40862E42) return h*__ieee754_exp(fabs(x));
w = __ieee754_exp(0.5*fabs(x));
extern double __ieee754_exp __P((double));
r = __ieee754_exp(-z*z-0.5625)*__ieee754_exp((z-x)*(z+x)+R/S);
r = __ieee754_exp(-z*z-0.5625)*
__ieee754_exp((z-x)*(z+x)+R/S);
return __ieee754_exp(x);
z = __ieee754_exp(x);