[GHC] #8695: Arithmetic overflow from (minBound :: Int) `quot` (-1)
GHC
ghc-devs at haskell.org
Tue Jan 28 23:45:13 UTC 2014
#8695: Arithmetic overflow from (minBound :: Int) `quot` (-1)
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Reporter: rleslie | Owner:
Type: bug | Status: patch
Priority: normal | Milestone: 7.8.1
Component: libraries/haskell2010 | Version: 7.6.3
Resolution: | Keywords:
Operating System: Unknown/Multiple | Architecture:
Type of failure: Incorrect result at runtime | Unknown/Multiple
Test Case: | Difficulty:
Blocking: | Unknown
| Blocked By:
| Related Tickets: #1042
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Comment (by rwbarton):
Basically, I don't agree that `minBound :: Int` is a sensible value for
`div minBound (-1) :: Int`. Division and modular arithmetic are
fundamentally incompatible, so if you are using `div` or `quot` on `Int`s,
you are not using `Int` for modular arithmetic but rather to compute more
efficiently with integers that happen to be small. And as integers,
`-2147483648` divided by `-1` is not `-2147483648`.
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8695#comment:24>
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