#14068: Loopification using join points -------------------------------------+------------------------------------- Reporter: nomeata | Owner: nomeata Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: JoinPoints Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #13966 #14067 | Differential Rev(s): Phab:D3811 #14827 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Yes, the entire join-ceiling machinery is wonky. I have a long-gestated patch about this, not yet completed alas, but this conversation may help me to make progress on it. I think float-out should not be moving join points at all -- except perhaps if they can go all the way to top level. Why top level? Well * Then the function it was part of before becomes smaller, and hence may inline. * At top level there is no closure to allocate. I suppose that if lifted to top level then it might be loopified afresh. Question: how beneficial is it to loopify a top-level function? Danger: once loopified, it becomes non-recursive and might be inlined again -- which would be funny but not very productive. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14068#comment:51 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler