[GHC] #9961: compile-time performance regression compiling genprimcode

#9961: compile-time performance regression compiling genprimcode -------------------------------------+------------------------------------- Reporter: hvr | Owner: simonpj Type: bug | Status: new Priority: normal | Milestone: 7.10.1 Component: Compiler | Version: 7.10.1-rc1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- compiling `utils/genprimopcode` (where compiling the Alex-generated Lexer takes up the most amount of time) with GHC 7.8.4: ``` $ time /opt/ghc/7.8.4/bin/ghc -Rghc-timing --make -O Main.hs [1 of 5] Compiling ParserM ( ParserM.hs, ParserM.o ) [2 of 5] Compiling Lexer ( Lexer.hs, Lexer.o ) [3 of 5] Compiling Syntax ( Syntax.hs, Syntax.o ) [4 of 5] Compiling Parser ( Parser.hs, Parser.o ) [5 of 5] Compiling Main ( Main.hs, Main.o ) Linking Main ... <> real 0m15.331s user 0m15.173s sys 0m0.172s ``` (btw, is it ok that GC takes up so much?) the same with a GHC 7.10 snapshot takes *alot* longer: ``` $ time /opt/ghc/7.10.1/bin/ghc -Rghc-timing --make -O Main.hs [1 of 5] Compiling ParserM ( ParserM.hs, ParserM.o ) [2 of 5] Compiling Lexer ( Lexer.hs, Lexer.o ) [3 of 5] Compiling Syntax ( Syntax.hs, Syntax.o ) [4 of 5] Compiling Parser ( Parser.hs, Parser.o ) [5 of 5] Compiling Main ( Main.hs, Main.o ) Linking Main ... <> real 5m17.061s user 5m16.702s sys 0m0.499s ``` ...and here the GC/MUT ratio is even more off. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9961 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler