Multiply a floating-point number by an integral power of FLT_RADIX.
double __far scalbn(double x, int n); (C99)
Returns the value calculated by x x FLT_RADIXn.
When x is a Not-a-Number (NaN), scalbn returns a Not-a-Number (NaN) and sets macro EDOM to global variable errno.
If an underflow or overflow occurs as a result of executing scalbn, it sets macro ERANGE to global variable errno. If an underflow occurs, scalbn returns an denormal number. If an overflow occurs, it returns ∞.
Multiply a floating-point number by an integral power of FLT_RADIX.