#14211: Compiler is unable to INLINE as well as the programmer can manually -------------------------------------+------------------------------------- Reporter: harendra | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: | StaticArgumentTransformation, | Inlining 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: | -------------------------------------+------------------------------------- Changes (by mpickering): * keywords: => StaticArgumentTransformation, Inlining Comment: `bindWith` is a self-recursive function so GHC won't inline it by itself. If you rewrite `bindWith` to {{{ bindWith :: (forall c. AsyncT m c -> AsyncT m c -> AsyncT m c) -> AsyncT m a -> (a -> AsyncT m b) -> AsyncT m b bindWith k m f = go m where go (AsyncT m) = AsyncT $ \_ stp yld -> let run x = (runAsyncT x) Nothing stp yld yield a _ Nothing = run $ f a yield a _ (Just r) = run $ f a `k` (go r) in m Nothing stp yield }}} so it delegates the recursion to the `go` function then it seems like the performance is the same. This is the transformation the static argument transformation is meant to achieve (turned on by `-fstatic-argument-transformation`). It didn't seem to work just by turning on this flag but I don't have time to investigate more now. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14211#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler