Re: [GHC] #8852: 7.8.1 uses a lot of memory when compiling attoparsec programs using <|>

#8852: 7.8.1 uses a lot of memory when compiling attoparsec programs using <|> -------------------------------------+------------------------------------- Reporter: joelteon | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.1-rc2 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: Compile- | Blocked By: time performance bug | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones ): In [changeset:"af4bc31c50c873344a2426d4be842f92edf17019/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="af4bc31c50c873344a2426d4be842f92edf17019" Do not duplicate call information in SpecConstr (Trac #8852) This long-standing and egregious bug meant that call information was being gratuitously copied, leading to an exponential blowup in the number of calls to be examined when function definitions are deeply nested. That is what has been causing the blowup in SpecConstr's running time, not (as I had previously supposed) generating very large code. See Note [spec_usg includes rhs_usg] }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8852#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler