Guardian C Library Calls Reference Manual

Reference to Library Calls

Guardian TNS C Library Calls Reference Manual—128833 3-103

ldexp

The ldexp function multiplies a floating-point number by an integral power of 2.

expr1

is an expression of type double.

expr2

is an expression of type int.

Return Value

is the value expr1*2expr2. If an overflow occurs, ldexp returns the value

HUGE_VAL. If an underflow occurs, it returns the value zero. In either of these

cases, ldexp sets errno to ERANGE (a range error).

Example

This example prints “The result is 4.920000.”:

#include <mathh>

#include <stdioh>

int main(void)

{

double r, x;

int i;

x = 1.23;

i = 2;

r = ldexp(x, i);

printf("The result is %f.", r);

}

#include <mathh>

double ldexp(double expr1, int expr2);