[GHC] #12640: Class member functions not substituted for MultiParamTypeClasses

[GHC]

#12640: Class member functions not substituted for MultiParamTypeClasses
-------------------------------------+-------------------------------------
        Reporter:  jeremy-list       |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by akio):

 Changing the `INLINE [2]` to `INLINE [1]` allows the rule to fire.

 I believe the issue is that an `INLINE [2]` is essentially the same as an
 `INLINE` with no phase specifier, because by default `2` is the first
 simplifier phase.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12640#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler