#10400: Run time increases by 40% in fractal plotter core loop -------------------------------------+------------------------------------- Reporter: saffroy | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 Resolution: | Keywords: Operating System: Linux | Architecture: x86_64 Type of failure: Runtime | (amd64) performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by nomeata): Thanks! Looks interesting. Have you compared the RTS stats (pass `+RTS -s` to your binary)? Have you compiled your program with profiling enabled, and created a profile (`+RTS -p`), and compared that? Finally, you could compare the produce Core (compile with of `-ddump- simpl`) for obvious differences. Is there a noticable difference whether you use `take n (repeat ..)` or `replicate n ...`? If so, maybe some list fusion is happening or not happening. That should be observable in the RTS stats (number of allocations), or in the Core. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10400#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler