[Haskell-cafe] Detecting numeric overflows

[Ryan Ingram]

Sure, but it's easy to roll your own from those primitives:

{-# LANGUAGE MagicHash, UnboxedTuples #-}
import GHC.Exts

addCarry :: Int -> Int -> (Int, Bool)
addCarry (I# x) (I# y) = case addIntC# x y of
     (# s, c #) -> case c of
         0# -> (I# s, False)
         _ -> (I# s, True)

or something along those lines.

  -- ryan

On Mon, Jul 30, 2012 at 1:43 PM, Евгений Пермяков <permeakra at gmail.com>wrote:

> On 07/31/2012 12:04 AM, Artyom Kazak wrote:
>
>> 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.
>>>
>>
>> ______________________________**_________________
>> Haskell-Cafe mailing list
>> Haskell-Cafe at haskell.org
>> http://www.haskell.org/**mailman/listinfo/haskell-cafe<http://www.haskell.org/mailman/listinfo/haskell-cafe>
>>
> Still no way to detect overflow in *.
>
> Strangely enough, I found some relevant descriptions in *.pp in dev
> branch, so I expect them in 7.6.1. They applies to native-size Word and Int
> only.
>
>
> ______________________________**_________________
> Haskell-Cafe mailing list
> Haskell-Cafe at haskell.org
> http://www.haskell.org/**mailman/listinfo/haskell-cafe<http://www.haskell.org/mailman/listinfo/haskell-cafe>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/haskell-cafe/attachments/20120731/860f1020/attachment.htm>