[GHC] #8095: TypeFamilies painfully slow

[GHC]

#8095: TypeFamilies painfully slow
-------------------------------------+-------------------------------------
        Reporter:  MikeIzbicki       |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  high              |               Milestone:  7.12.1
       Component:  Compiler (Type    |                 Version:  7.6.3
  checker)                           |                Keywords:
      Resolution:                    |            Architecture:
Operating System:  Unknown/Multiple  |  Unknown/Multiple
 Type of failure:  Compile-time      |               Test Case:
  performance bug                    |                Blocking:
      Blocked By:                    |  Differential Revisions:
 Related Tickets:  5321              |
-------------------------------------+-------------------------------------

Comment (by archblob):

 These are times measured on an i3-2100 CPU @ 3.10GHz running
 Ubuntu 15.04 and GHC 7.10.1 :
 ||= input  =||=  real  =||
 ||200 a a   || 0m0.609s ||
 ||300 a a   || 0m0.689s ||
 ||400 a a   || 0m0.884s ||
 ||500 a a   || 0m0.942s ||
 ||200 b a   || 0m2.028s ||
 ||200 c a   || 0m1.092s ||
 ||10000 a d || 0m1.978s ||

 They are grately improved and needed no stack adjustment.
 Tail-recursive variant is still a lot slower.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8095#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler