#14186: CSE fails to CSE -------------------------------------+------------------------------------- Reporter: nomeata | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.3 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: -------------------------------------+------------------------------------- Consider this code: {{{ module CSEBug where data Succs a = Succs a [a] instance Functor Succs where fmap f (Succs o s) = Succs (f o) (map f s) foo, bar :: (a -> b) -> (b -> c) -> Succs a -> Succs c foo f g x = fmap (g . f) x bar f g x = fmap (g . f) x }}} If I compile this with `-O`, `foo` and `bar` are not CSEd, which can be seen with `-ddump-cse`. Removing either the first or the second argument of `Succs` makes CSE work. Is there a size limit on CSE? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14186 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler