LDEXP(3) Library Functions Manual LDEXP(3)

ldexp — load exponent of a floating point number

#include <math.h>

double ldexp(double x, int exp);

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

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.

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 and errno may be set to [EDOM].

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, 0 is returned and errno may be set to [ERANGE].

The ldexp() function will fail if:

The value to be returned would have caused overflow.

The ldexp() function may fail if:

The argument x is NaN.
The value to be returned would have caused underflow.

No other errors will occur.

None.

None.

None.

frexp(3) , isnan(3) , <math.h> .

Derived from Issue 1 of the SVID.

February 1997 posix.fail