#14667: Compiling a function with a lot of alternatives bottlenecks on insertIntHeap -------------------------------------+------------------------------------- Reporter: niteria | Owner: niteria Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonmar): That diff of mine basically replaces a set with a list, so it's not entirely surprising that it can be responsible for something being accidentally quadratic. I think at the time it was a small improvement because N was small in everything I measured, and for small N a list is a bit faster than an IntSet, but again it's not entirely surprising to find that it's possible to make it behave badly. I'm totally fine with reverting it, but do a nofib run first to check for adverse effects. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14667#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler