// verify precision of result for extreme inputs
	if f := Remainder(5.9790119248836734e+200, 1.1258465975523544); -0.4810497673014966 != f {
		t.Errorf("Remainder(5.9790119248836734e+200, 1.1258465975523544) = %g, want -0.4810497673014966", f)
	}
	// verify that sign is correct when r == 0.
	test := func(x, y float64) {
		if r := Remainder(x, y); r == 0 && Signbit(r) != Signbit(x) {