[GHC] #12234: 'deriving Eq' on recursive datatype makes ghc eat a lot of CPU and RAM

[GHC]

#12234: 'deriving Eq' on recursive datatype makes ghc eat a lot of CPU and RAM
-------------------------------------+-------------------------------------
        Reporter:  slyfox            |                Owner:
            Type:  bug               |               Status:  merge
        Priority:  normal            |            Milestone:  8.0.3
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:  deriving-perf
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Compile-time      |            Test Case:
  performance bug                    |  perf/should_compile/T12234
      Blocked By:                    |             Blocking:
 Related Tickets:  #13056            |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Ryan Scott <ryan.gl.scott@…>):

 In [changeset:"508811004d1806b28a91c3ff4a5c2247e2ad4655/ghc" 5088110/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="508811004d1806b28a91c3ff4a5c2247e2ad4655"
 Add performance test for #13056

 This performance regression was fixed by commit
 517d03e41b4f5c144d1ad684539340421be2be2a (#12234). Let's add a performance
 test
 to ensure that it doesn't break again.
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12234#comment:15>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler