[GHC] #14152: Float exit paths out of recursive functions

[GHC]

#14152: Float exit paths out of recursive functions
-------------------------------------+-------------------------------------
        Reporter:  nomeata           |                Owner:  (none)
            Type:  task              |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:  JoinPoints
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #14137 #10918     |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by simonpj):

 What's this (in `Exitify`):
 {{{
   where
     exit_id_tmpl = mkSysLocal (fsLit "exit") initExitJoinUnique ty
                     `asJoinId` join_arity
                     `setIdOccInfo` exit_occ_info

     -- See Note [Do not inline exit join points]
     exit_occ_info =
         OneOcc { occ_in_lam = True
                , occ_one_br = True
                , occ_int_cxt = False
                , occ_tail = AlwaysTailCalled join_arity }
 }}}
 The occurrence analyser sets occ-info. No one else should.  What happens
 if you leave this out?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14152#comment:35>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler