[GHC] #12622: Unboxed static pointers lead to missing SPT entries

[GHC]

#12622: Unboxed static pointers lead to missing SPT entries
-------------------------------------+-------------------------------------
        Reporter:  mboes             |                Owner:
                                     |  facundo.dominguez
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2709
       Wiki Page:                    |  Phab:D2720
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Comment (by simonpj):

 Interesting.  In fact this "make it an exported Id" stuff can now be done
 later.  The Grand Plan comment in `SimplCore` says
 {{{
   The FloatOut pass is careful to produce an /exported/ Id for a floated
   'StaticPtr', so the binding is not removed by the simplifier (see
 #12207).
   E.g. the code for `f` above might look like

     static_ptr = StaticPtr <fingerprint> k
     f x = ...(staticKey static_ptr)...

   which might correctly be simplified to

     f x = ...<fingerprint>...

   BUT the top-level binding for static_ptr must remain, so that it can be
   collected to populate the Static Pointer Table.
 }}}
 But if we generate `sp = makeStatic e)` not `sp = StaticPtr blah blah`,
 then `(staticKey sp)` won't simplify, but will still use `sp`.  So no need
 for special treatment.  Hooray.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12622#comment:16>
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