let a1 = DoubleDouble::from_bits(op1);
let a2 = DoubleDouble::from_bits(op2);
assert_eq!(expected, a1.partial_cmp(&a2), "compare({:#x}, {:#x})", op1, op2,);
let a1 = DoubleDouble::from_bits(op1);
let a2 = DoubleDouble::from_bits(op2);
assert_eq!(expected, a1.partial_cmp(&a2), "compare({:#x}, {:#x})", op1, op2,);