#12506: Compile time regression in GHC 8. -------------------------------------+------------------------------------- Reporter: deech | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.0.1 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 tdammers): Replying to [comment:28 simonpj]:
I can confirm that this *is* a regression; I'm seeing ~34 seconds overall compilation time on 7.10.3, vs. ~341 seconds on GHC HEAD.
Aha! Excellent. Does that show on (some version of) the repro case test.hs?
PS: maybe comment:27 answers that affirmatively; I missed that.
Yes on both; `test1000.hs` is pretty much an exact replica of the code in the original test case, I really just unrolled the imports to get it into one file, and played with the number of repetitions in `main`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12506#comment:29 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler