#3677: Optimizer creates stack overflow on filtered CAF
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Reporter: jpet | Owner:
Type: bug | Status: new
Priority: normal | Component: Compiler
Version: 6.10.4 | Keywords:
Os: Windows | Testcase:
Architecture: x86 | Failure: Runtime crash
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The following code creates a stack overflow at -O1 or -O2, when running
with a moderately small stack (+RTS -K94k):
import Data.Bits
hmm :: [Integer]
hmm = filter (\n -> (n .&. (n-1))==0) [1..]
main = mapM_ print hmm
The lambda just picks out powers of two, so that filter will skip
increasingly long subsequences. It's the filter causing the overflow.
Changing hmm to [Int], or to be let-bound, or compiling with -O0 makes the
overflow go away. Using a 95k stack also makes the overflow go away.
(Below 95k, stack usage is linear with the length of the filtered-out
subsequence; then it seems to cap out.)
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3677>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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