These functions return the floating-point remainder r = x - n*y)
    when y is nonzero. The value n is the integral value nearest the
    exact value x/y. That is, n = rint(x/y).
    When |n - x/y| = 1/2, the value n is chosen to be even.
    The behavior of the remainder function is independent of the
    rounding mode.
    The remainder functions are functionally equivalent to the remquo
    functions.