-0 rational?

Hi *, I just ran into the following case:

fromRat (-0 :: Rational) :: Double 0.0

-0 :: Rational 0 % 1

How do I encode negative zero as a rational? The question come up as `CmmFloat` is defined as `CmmFloat Rational Width` in compiler/cmm/CmmExpr.hs. And my code generator thus turned (Int, Rational) into a floating point expression, and when trying to turn it into a `double` value, I ended up getting bad negative zeros. This makes me believe I can’t actually encode `-0` as a Rational, and such `CmmFloat` will never contain `-0`? Cheers, Moritz