So yes one could do it as a `CorePrep` tactic, but it's delicate; and we risk not getting the benefits because we don't implement the follow-on
#14295: tagToEnum# leads to some silly closures -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.4.1 Component: Compiler | Version: 8.2.1 Resolution: | Keywords: datacon-tags Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): Replying to [comment:11 simonpj]: transformations. What makes it delicate? For `quotInt#` et al, I don't imagine that there ''are'' many interesting follow-on transformations in most cases, although I could be wrong. For `tagToEnum#`, we should decide whether to "inline" in core2core. If we go to the trouble of a `quotInt#` cleanup in `CorePrep`, then we can just tack the `tagToEnum#` cleanup on in the same way. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14295#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler