[Haskell-cafe] Detecting numeric overflows

[Artyom Kazak]

Евгений Пермяков <permeakra at gmail.com> писал в своём письме Mon, 30 Jul  
2012 09:47:48 +0300:

> Can someone tell me if there are any primitives, that used to detect  
> machine type overflows, in ghc haskell ? I perfectly understand, that I  
> can build something based on preconditioning of variables, but this will  
> kill any performance, if needed.

In GHC.Prim — primitives addIntC# and subIntC#:

> addIntC# :: Int# -> Int# -> (#Int#, Int##)
> Add with carry. First member of result is (wrapped) sum; second member  
> is 0 iff no overflow occured.

> subIntC# :: Int# -> Int# -> (#Int#, Int##)
> Subtract with carry. First member of result is (wrapped) difference;  
> second member is 0 iff no overflow occured.