#12754: Adding an explicit export list halves compilation time. -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: bug | Status: new Priority: normal | Milestone: 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 mpickering): Bartosz game me the command he was using. {{{ rm A.{hs,o,hi}; python gen12754.py > A.hs && time ghc A.hs }}} and I ran the test again, here are my 4 runs. {{{ [1 of 1] Compiling A ( A.hs, A.o ) real 0m26.460s user 0m24.643s sys 0m0.711s ~/Documents/haskell/ghc:vim gen.py ~/Documents/haskell/ghc:rm A.{hs,o,hi}; python gen.py > A.hs && time ghc A.hs [1 of 1] Compiling A ( A.hs, A.o ) real 0m15.743s user 0m15.100s sys 0m0.402s ~/Documents/haskell/ghc:vim gen.py ~/Documents/haskell/ghc:rm A.{hs,o,hi}; python gen.py > A.hs && time ghc A.hs [1 of 1] Compiling A ( A.hs, A.o ) real 0m24.858s user 0m24.283s sys 0m0.392s ~/Documents/haskell/ghc:vim gen.py ~/Documents/haskell/ghc:rm A.{hs,o,hi}; python gen.py > A.hs && time ghc A.hs [1 of 1] Compiling A ( A.hs, A.o ) real 0m12.098s user 0m11.672s sys 0m0.321s }}} so I do see a big difference. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12754#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler