Re: [GHC] #12191: 7% allocation regression in Haddock performance tests

#12191: 7% allocation regression in Haddock performance tests -------------------------------------+------------------------------------- Reporter: bgamari | Owner: niteria Type: task | 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: #10482 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Bartosz Nitka ): In [changeset:"348f2dbb835b1208f601bb1e8daa1d1d54507eda/ghc" 348f2dbb/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="348f2dbb835b1208f601bb1e8daa1d1d54507eda" Make the Ord Module independent of Unique order (2nd try) The `Ord Module` instance currently uses `Unique`s for comparison. We don't want to use the `Unique` order because it can introduce nondeterminism. This switches `Ord ModuleName` and `Ord UnitId` to use lexicographic ordering making `Ord Module` deterministic transitively. I've run `nofib` and it doesn't make a measurable difference. See also Note [ModuleEnv determinism and performance]. This fixes #12191 - the regression, that the previous version of this patch had. Test Plan: ./validate run nofib: P112 Reviewers: simonmar, bgamari, austin Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2354 GHC Trac Issues: #4012, #12191 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12191#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler