[GHC] #7968: fft2 benchmark sometimes fails (nofib)

[GHC]

#7968: fft2 benchmark sometimes fails (nofib)
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Reporter:  jstolarek                    |          Owner:                       
    Type:  bug                          |         Status:  new                  
Priority:  normal                       |      Component:  NoFib benchmark suite
 Version:  7.7                          |       Keywords:                       
      Os:  Linux                        |   Architecture:  x86_64 (amd64)       
 Failure:  Incorrect result at runtime  |      Blockedby:                       
Blocking:                               |        Related:                       
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Comment(by jstolarek):

 When I was reporting this bug I didn't notice that the values that are
 being matched are almost zero - no wonder that round-off errors might lead
 to slightly different results. It seems that whoever wrote this benchmark
 is well aware of this, because there are thirteen (sic!) different files
 with expected output values! This in itself shows that the expected
 results are not stable.

 Anyway, I tried to be smart and changed the expected values in
 fft2.stdout7 to what I get on my machine, but now mandel benchmark fails:

 {{{
 real    0m3.537s
 user    0m3.504s
 sys     0m0.021s
 ././mandel < mandel.stdin
 expected stdout not matched by reality
 Binary files mandel.stdout-mingw and /tmp/runtest16086.1 differ
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7968#comment:1>
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