#13397: Optimise calls to tagToEnum# -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Ever since we started using `Int#` to represent booleans unboxed (see [wiki:PrimBool]) we have had lots of code looking like {{{ case tagToEnum# (a ># b) of False -> e1 True -> e2 }}} It would be better (less code to optimise, more straightforward, more direct) to optimise this to {{{ case a ># b of DEFAULT -> e1 1# -> e2 }}} Happily, we already have a nice spot to do so: the `caseRules` function in `SimplUtils`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13397 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler