[GHC] #7684: cgrun071 segfaults

[GHC]

#7684: cgrun071 segfaults
----------------------------------+----------------------------------
        Reporter:  tibbe          |            Owner:  leroux
            Type:  bug            |           Status:  new
        Priority:  normal         |        Milestone:  7.8.1
       Component:  Compiler       |          Version:  7.7
      Resolution:                 |         Keywords:
Operating System:  MacOS X        |     Architecture:  x86_64 (amd64)
 Type of failure:  Runtime crash  |       Difficulty:  Unknown
       Test Case:  cgrun071       |       Blocked By:
        Blocking:                 |  Related Tickets:
----------------------------------+----------------------------------

Comment (by tibbe):

 As you can see from the assembly the `POPCNT` instruction is never used
 and can't thus be the cause of the segfault. Besides, if I remember
 correctly incorrect instructions give an "illegal instruction" crash on OS
 X, not a segfault. The ghc-prim function is called

 {{{
     call hs_popcnt16
 }}}

 so the issue is most likely to do with that call (e.g. narrowing).

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7684#comment:21>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler