#11196: TypeInType performance regressions -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: high | Milestone: 8.0.2 Component: Compiler | Version: 7.11 Resolution: | Keywords: TypeInType 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: | -------------------------------------+------------------------------------- Changes (by thomie): * failure: None/Unknown => Compile-time performance bug @@ -12,1 +12,1 @@ - * T9872d, '''down''' by 91.8% (see below) + * T9872d, '''down''' by 22% (see below) New description: This ticket is to track the handful of performance regressions seen with the addition of `TypeInType`. It is quite possibly a good idea to break these out into separate tickets, but until we investigate, they're all bundled here. The regressions are (all in bytes allocated, unless otherwise noted): * T3064, up by 14.9% * T5030, up by 61.8% * T5837, up by 13% * T5321Fun, up by 11% * T5631, up by 39% * T9872d, '''down''' by 22% (see below) * T9872a, up by 33.6% * T9872c, up by 59.4% * T9872b, up by 49.4% * T9675, up by 29.7%, and peak megabytes allocated up by 28.4% * haddock.base, up by 12.4% * haddock.Cabal, up by 9.5% I did add an optimization around type family reduction (the function `zonk_eq_types` in !TcCanonical) that could cause such a drastic reduction. -- Comment: For the record: T9872d went down by 22% (the description first claimed 92%, which probably resulted from a typo), from 726679784 to 566134504 bytes allocated. Since then it has dropped another 8% to 506691240 (64-bit). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11196#comment:16 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler