#7542: GHC doesn't optimize (strict) composition with id ---------------------------------+------------------------------------------ Reporter: shachaf | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.1 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Runtime performance bug Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ Comment(by simonpj): The previous two commits improve the situation a bit; both were triggered by looking at the code from this example, thanks. I'm far from sure that we get perfect code now. But I'm also convinced that this is the wrong way to solve this problem: check out [wiki:NewtypeWrappers]. Meanwhile do have a go with HEAD and see if you get better code now. Simon -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7542#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler