#8695: Arithmetic overflow from (minBound :: Int) `quot` (-1) ------------------------------------------------+-------------------------- 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 ------------------------------------------------+-------------------------- Comment (by rwbarton): Division is a totally different kind of operation than addition, subtraction and multiplication! The reason that "performing arithmetic mod 2^n^" is sensible for the latter three is that they respect equality mod 2^n^ (Z/2^n^Z is a ring). Division does not. You can't take the Euclidean domain approach to defining division mod 2^n^ anyways because there are extra solutions, e.g. for `div 100 3` (mod 2^32^) we have 100 = 3 * 33 + 1, but also 100 = 3 * 1431655798 + 2 and 100 = 3 * 2863311564 + 0. The only sensible notion of division mod 2^n^ is modular division by odd numbers, but that's clearly not the role of `div` or `quot`. So I don't give any weight to arguments-by-analogy such as "addition, subtraction and multiplication can be computed by injecting into Integer, performing the operation and reducing the result to an Int, hence so too should division be". -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8695#comment:23 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler