[GHC] #11735: Optimize coercionKind

[GHC]

#11735: Optimize coercionKind
-------------------------------------+-------------------------------------
        Reporter:  goldfire          |                Owner:  (none)
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by tdammers):

 Replying to [comment:67 Simon Peyton Jones <simonpj@…>]:
 > In [changeset:"db5a4b83b14bf4f1adb417b7664347fdaf637fd6/ghc"
 db5a4b83/ghc]:
 > {{{
 > #!CommitTicketReference repository="ghc"
 revision="db5a4b83b14bf4f1adb417b7664347fdaf637fd6"
 > Re-center improved perf for T3064
 >
 > There's a 6% reduction in allocation on T3064.  I think it's due to
 >
 >   commit e4ab65bd57b2c39f4af52879654514bb6d5b42a0
 >   Author: Tobias Dammers <tdammers at gmail.com>
 >   Date:   Wed Jan 31 21:39:45 2018 -0500
 >
 >       Optimize coercionKind (Trac #11735)
 >
 > I'm not certain -- but, hey, it's good news
 > }}}

 We already knew that this change gives us insane improvements in at least
 one case, so I guess the fact that we see this reflected somewhere in the
 test suite is good, I presume. Wonder what T3064 does and whether it's
 related.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11735#comment:68>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler