NAME

ldexp - load exponent of a floating point number

 SYNOPSIS

#include <math.h>

double ldexp(double x, int exp);

 DESCRIPTION

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.

 RETURN VALUE

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].

 ERRORS

The ldexp() function will fail if:

[ERANGE]

The value to be returned would have caused overflow.

The ldexp() function may fail if:

[EDOM]

The argument x is NaN.

[ERANGE]

The value to be returned would have caused underflow.

No other errors will occur.

 EXAMPLES

None.

 APPLICATION USAGE

None.

 FUTURE DIRECTIONS

None.

 SEE ALSO

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

DERIVATION

Derived from Issue 1 of the SVID.