The
ldexp() function returns the value of
x times 2 raised to the power
exp.
If the input
x is a NaN, infinity, or 0.0, it is returned unchanged.
If the result would cause an overflow, the global variable
errno is set to
ERANGE and infinity is returned, with the same sign as
x.
If the result would cause underflow to 0.0, the global variable
errno is set to
ERANGE and the value 0.0 is returned.