realToFrac between Float and Double gives different results depending on compile flags

The following simple program gives different results depending on optimization level with GHC 8.6.4

moe, larry, curly :: Double
moe = 0/0
larry = 1/0
curly = -1/0

dancingLady = [moe,larry,curly]
helloPop = map realToFrac dancingLady :: [Float]
planeNuts = map realToFrac helloPop :: [Double]

main = do
  print dancingLady
  print helloPop
  print planeNuts

With -O1 and -O2 it prints the expected

[NaN,Infinity,-Infinity]
[NaN,Infinity,-Infinity]
[NaN,Infinity,-Infinity]

but with -O0 or when interpreted via ghci it prints

[NaN,Infinity,-Infinity]
[-Infinity,Infinity,-Infinity]
[-3.402823669209385e38,3.402823669209385e38,-3.402823669209385e38]

:-(

I hope you agree this is a serious bug. At the very least I would expect the conversion to be consistent, i.e. not a function of the optimization level.