[GHC] #11810: Filtering of cost-center profiler output no longer works

[GHC]

#11810: Filtering of cost-center profiler output no longer works
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           Reporter:  bgamari        |             Owner:
               Type:  bug            |            Status:  new
           Priority:  highest        |         Milestone:  8.0.1
          Component:  Profiling      |           Version:  8.0.1-rc3
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  Incorrect result
  Unknown/Multiple                   |  at runtime
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 With the following testcase,
 {{{#!hs
 import Control.Monad (replicateM)

 main :: IO ()
 main = do
     let xs = replicate 10000000 $ 42
     print $ length xs
     print $ sum xs
 }}}

 Running like this,
 {{{
 ghc -prof -auto-all Hi.hs && ./Hi +RTS -hy[] -hc
 }}}
 with 7.10.3 produces a useful profile with the output one would expect.
 8.0.1-rc2, on the other hand produces empty samples.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11810>
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