[GHC] #10108: Dramatic slowdown with -O2 bytestream and list streams combined.
GHC
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Sun Feb 22 18:27:32 UTC 2015
#10108: Dramatic slowdown with -O2 bytestream and list streams combined.
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Reporter: Truman | Owner:
Type: bug | Status: new
Priority: normal | Milestone: 7.10.2
Component: Compiler | Version: 7.8.4
Keywords: | Operating System: Linux
Architecture: | Type of failure: Runtime
Unknown/Multiple | performance bug
Test Case: | Blocked By:
break_in.hs | Related Tickets:
Blocking: |
Differential Revisions: |
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In a small testcase intended to filter log files from stdin, I
found that using bytestreams and list streams in combination worked
fine when compiled without optimization, but runtime performance slowed
down by a factor of about 3600 when I compiled with -O2. Changing the
import of Data.List.Stream to Data.List gets rid of the problem.
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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10108>
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