#8900: Strictness analysis regression --------------------------------------------+------------------------------ Reporter: tibbe | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.8.1-rc2 Resolution: fixed | Keywords: Operating System: MacOS X | Architecture: x86_64 Type of failure: Runtime performance bug | (amd64) Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: --------------------------------------------+------------------------------ Comment (by tibbe): Replying to [comment:21 simonpj]:
Comment 9 you said "While the extra case is definitely a regression, it doesn't seem to be the cause of the time difference". and in comment 14 "without the extra case there is still a small difference".
Is that still true? If so there might still be something to track down.
There's still a (quite small) difference in mutator time. I haven't had time to investigate it. The Cmm output by 7.6.3 (attachment:HashMapInsert-7.6.3.dump-opt-cmm) and HEAD (attachment:HashMapInsert-HEAD.dump-opt-cmm) look quite a bit different, at least superficially. For example, 7.6.3 has the core loop split into two functions, `$wpoly_go_info` and `s30b_ret`, while HEAD has just one function, `$wpoly_go_entry`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8900#comment:22 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler