#7258: Compiling DynFlags is jolly slow -------------------------------------+------------------------------------- Reporter: simonpj | Owner: simonpj Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.1 Resolution: | Keywords: deriving-perf 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:69 simonpj]:
Is the large Cmm accounted for by the big Core-to-Cmm ratio, or do these examples also have Core sizes that scale badly (look at term size only)?
I'm guessing that the Core size does not scale badly. If that was so our questions would be
* Why do we generate so much Cmm per unit of Core * Can we make `sink` scale better
Both are worth working on.
https://ghc.haskell.org/trac/ghc/attachment/ticket/7258/ghc-large-record- types-core-size.png suggests Core size has a slight nonlinearity to it, the behavior is roughly the same for all examples, so I believe your guess that Core size doesn't scale as badly as C-- size does is justified. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7258#comment:71 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler