[GHC] #7411: Exceptions are optimized away in certain situations

[GHC]

#7411: Exceptions are optimized away in certain situations
-------------------------------------+-------------------------------------
        Reporter:  SimonHengel       |                Owner:  tdammers
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  7.6.1
      Resolution:                    |             Keywords:  seq, deepseq,
                                     |  evaluate, exceptions
Operating System:  Linux             |         Architecture:  x86_64
                                     |  (amd64)
 Type of failure:  Incorrect result  |            Test Case:
  at runtime                         |  simplCore/should_fail/T7411
      Blocked By:                    |             Blocking:
 Related Tickets:  #5129             |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 A program that might run slower without the state hack is
 {{{
 f :: Char -> IO ()
 f 'x' = return ()
 f c   = putChar c
 }}}
 Now call that `f` many times.  Without the state hack I think it'll have
 arity 1, returning a lambda that does the I/O.

 We must find out what happens with fasta, yes, but what are the perf
 results from nofib?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7411#comment:37>
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