#14683: Slow compile times for Happy-generated source -------------------------------------+------------------------------------- Reporter: harpocrates | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.2.2 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 alexbiehl): Tobias, I saw you mentioning #7258 here. I ran over `Grammar.hs` with my sampling code from for #14461: - there are 245 non-toplevel StgRhsClosures - the deepest StgRhsClosure is nested 5 levels - Of that 245, - 168 have 0 free variables - 53 have 1 free variables - 16 have 2 free variables - 6 have 3 free variables - 1 has 4 free variables - 1 has 7 free variables - - 206 share 0 free variables with their parent - 32 share 1 free variable with their parent - 6 share 2 free variables with their parent - 1 shares 3 free variables with their parent I think this is not related to code generation. My timing shows most of the time is spent before CoreToStg. Codegen is a lot less. Our pathological cases #7258 had A LOT more (basically around 100 StgRhsClosures sharing around 150 fvs with their parents) free variable business going on. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14683#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler