Primitive constant unfolding
Examining the core generated by ghc with -O2 on a numerical code, I saw things like :
case GHC.Prim.<## x_aB9 (GHC.Prim.**## 2.0 -1021.0) of _ {...
This code being executed each time my code performs an addition ! GHC does not seem to unfold the constants right with at least **##. By the way, it should definitely be possible to specify a Double# constant in hexadecimal.