+
+exprBotStrictness_maybe :: CoreExpr -> Maybe (Arity, StrictSig)
+-- A cheap and cheerful function that identifies bottoming functions
+-- and gives them a suitable strictness signatures. It's used during
+-- float-out
+exprBotStrictness_maybe e
+ = case arityType False e of
+ AT _ ATop -> Nothing
+ AT a ABot -> Just (a, mkStrictSig (mkTopDmdType (replicate a topDmd) BotRes))