HP-UX Reference (11i v1 05/09) - 3 Library Functions A-M (vol 6)

ldexp(3M) ldexp(3M)

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

To use this function, make sure your program includes <

math.h>, and link in the math library by specify-

ing

-lm on the compiler or linker command line.

RETURN VALUE

Upon successful completion, the ldexp() function returns a

double representing the value x multiplied

by 2 raised to the power exp.

If x is NaN,

ldexp() returns NaN.

If the correct value after rounding would be smaller in magnitude than MINDOUBLE, ldexp() returns

zero.

If the correct value would overﬂow,

ldexp() returns ±HUGE_VAL (according to the sign of x) and sets

errno to [ERANGE].

ERRORS

If ldexp() fails, errno is set to one of the following values.

[ERANGE] The correct value would overﬂow.