ldexp() multiplies a floating-point number, x, by 2**n.

                           Entry-Point Names

    Generic
    Function   Data Type   OpenVMS        Tru64 UNIX
    Name       Required

    ldexp      S_FLOAT     math$ldexp_s   ldexpf
               T_FLOAT     math$ldexp_t   ldexp
               X_FLOAT     math$ldexp_x   ldexpl
               F_FLOAT     math$ldexp_f
               G_FLOAT     math$ldexp_g