#7052: Numeric types’ Read instances use exponential CPU/memory
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Reporter: andersk | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: libraries/base | Version: 7.4.2
Resolution: | Keywords:
Os: Unknown/Multiple | Architecture: Unknown/Multiple
Failure: Runtime performance bug | Difficulty: Unknown
Testcase: | Blockedby:
Blocking: | Related: #5688
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Changes (by andersk):
* status: closed => new
* version: 7.4.1 => 7.4.2
* resolution: fixed =>
Comment:
Okay hold on, there’s still something wrong in 7.4.2 (I just downloaded
ghc-7.4.2-x86_64-unknown-linux.tar.bz2).
{{{
> read ("1e" ++ show (2^63 - 2)) :: Double
Infinity -- Fine.
> read ("1e" ++ show (2^63 - 1)) :: Double
0.0 -- What?
> read ("1e" ++ show (2^64 - 2^10 - 2)) :: Double
0.0 -- What?
> read ("1e" ++ show (2^64 - 2^10 - 1)) :: Double
-- Memory-eating infinite loop!
}}}
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7052#comment:3>
GHC <http://www.haskell.org/ghc/>
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