#7556: build/fold causes with ByteString unpack causes huge memory leak
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Reporter: glguy | Owner:
Type: bug | Status: new
Priority: normal | Component: libraries/base
Version: 7.6.1 | Keywords:
Os: Unknown/Multiple | Architecture: Unknown/Multiple
Failure: Runtime performance bug | Blockedby:
Blocking: | Related:
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Comment(by glguy):
{{{
module Main where
import qualified Data.ByteString as B
import Data.Word (Word8)
-- works fast without optimizations
-- with optimizations this has a space leak
-- seems related to fold/build fusion in foldr/unpack
main :: IO ()
main = do
let b = B.replicate 100000000 1
print $ B.length b
print $ example1 b -- fast
print $ example2 b -- slow
search :: [Word8] -> Bool
search [] = False
search (x:xs) = x == 1 || search xs
example1, example2 :: B.ByteString -> Bool
example1 = search . B.unpack
example2 = foldr (\x xs -> x == 1 || xs) False . B.unpack
}}}
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7556#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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