The ldexp() function computes the quantity x* 2^exp.

Upon successful completion, ldexp() returns a double representing the value x multiplied by 2 raised to the power exp.

If the value of x is NaN, NaN is returned.

If ldexp() would cause overflow, +-HUGE_VAL is returned (according to the sign of x), and errno is set to ERANGE.

If ldexp() would cause underflow to 0.0, 0 is returned and errno may be set to ERANGE.

The ldexp() function will fail if:

ERANGE

The value to be returned would have caused overflow.

The ldexp() function may fail if:

ERANGE

The value to be returned would have caused underflow.

An application wishing to check for error situations should set errno to 0 before calling ldexp(). If errno is non-zero on return, or the return value is NaN, an error has occurred.

See attributes(5) for descriptions of the following attributes:

frexp(3C), isnan(3M), attributes(5)