ldexp
double ldexp(double, int);
value = ldexp((double)high_mantissa, exponent);
value += ldexp((double)low_mantissa, exponent);
return (realnode((REAL)ldexp(result, expon-15)));
inline float ldexp(float __X, int __Y) { return __ldexpf(__X, __Y); }
inline long double ldexp(long double __X, int __Y) {
extern double ldexp(double, int);
using std::ldexp;
extern double ldexp __P((double, int));