Integer Overflow

Tim Peters tim at zope.com
Tue Nov 27 20:59:31 CET 2001


[Skip Montanaro]
> In the current 2.2 beta, int operations that would overflow
> silently return longs:
>
>     >>> 3**100
>     515377520732011331036461129765621272702107522001L

[Fernando Perez]
> Just curious: how bad is the performance impact from this (if any)?

Python was always checking for overflow, so a non-overflowing case is as
quick as before.  The new expense when it does overflow is subtle:  you can
still get optional warnings about overflows in 2.2, so an overflow takes an
expensive trip through the warning-suppression machinery to see whether or
not you want a warning.  I expect that option will go away in 2.3.





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