#9872: Runing type functions is too slow -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Resolution: fixed | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: | Blocked By: None/Unknown | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by jstolarek): I mentioned on ghc-devs that I witnessed exponential compile times for type families. I just built the latest HEAD and I see that the problem is gone. With my test case I get the following dependency between input size and compile time: ||= Input size =||= GHC 7.8.4 RC1 =||= GHC HEAD || || 64 || 1.2s || 0.6s || || 128 || 11.1s || 1.3s || || 256 || 1m41s || 3.7s || Compiling with GHC 7.8.4 required passing `-ftype-function-depth=1000` (perhaps a smaller value would work, but the default one was too low). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9872#comment:19 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler