#11064: Call Arity has the trivial application case wrong -------------------------------------+------------------------------------- Reporter: nomeata | Owner: nomeata Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 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: -------------------------------------+------------------------------------- In `e x`, the result of `x` is not shared in contrast to `e (f x)`, where CorePrep will turn it into `let y = f x in e x`. So in {{{ let f = ... in e (f x) }}} we know that f is called at most once, but in {{{ let f = ... in e f }}} we do not know that. Previously Call Arity would assume that in `e x`, `x` is evaluated at most once. This rarely would make a difference (the argument `x` is analized with an incoming arity of 0, so no eta-expansion would be done anyways), but of course this should still be fixed. I just validated a patch and will push shortly. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11064 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler