Prevent optimization from tempering with unsafePerformIO

Hello, I am writing a compiler from the functional logic language Curry to Haskell. As the result is a real extension of Haskell, there has to be SOME side effect involved. Unfortunately, this seems to prevent me from using any of ghc's optimizations on the resulting code. I have tried for some time to invoke the no-inline pragmata, but they seem to have no effect at all. Recently at ICFP, Neil Mitchell told me that there definitely is a way to avoid this problem. But does anybody know how? Thanks for your help! Bernd Brassel