http://www.haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v:gcd

give a NB mentioning that (abs minBound == minBound) is possible for fixed-width types.

This holds, for example, at Int. It is also the case that (negate minBound == minBound).

Two questions:

  1) This behavior surprised me. Does it surprise enough people to include a warning in the Haddock for abs and negate? IE Here.

    http://www.haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#t:Num

  2) Is this a common behavior in other languages? My tinkering with gcc suggests it does not support the value -2^63, but instead bottoms out at (-2^63+1).

Thanks.