Re: [GHC] #3064: Very long compile times with type functions

6 Nov 2014

      #3064: Very long compile times with type functions
-------------------------------------------------+-------------------------
        Reporter:  simonpj                       |            Owner:
            Type:  bug                           |           Status:
        Priority:  low                           |  closed
       Component:  Compiler (Type checker)       |        Milestone:  7.6.1
      Resolution:  fixed                         |          Version:
Operating System:  Unknown/Multiple              |  6.10.1
 Type of failure:  Compile-time performance bug  |         Keywords:
       Test Case:  perf/compiler/T3064           |     Architecture:
        Blocking:                                |  Unknown/Multiple
                                                 |       Difficulty:
                                                 |  Unknown
                                                 |       Blocked By:
                                                 |  Related Tickets:
-------------------------------------------------+-------------------------

Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"096b7e664351d102cc9e15f3aa226a976af5dae2/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="096b7e664351d102cc9e15f3aa226a976af5dae2"
 Switch off lazy flattening (fix Trac #3064)

 See Note [Lazy flattening] in TcFlatten.

 Lazy flattening was an apparently good idea which actually made
 the type inference engine go a LOTS slower in T3064.  So I switched
 it off again.
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/3064#comment:17>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler