[Python-Dev] Memory size overflows

[Tim Peters]

[Gerald S. Williams]
> Well, I was done tweaking, but then I decided to try out one more
> performance tweak. This is in desperate need of commenting, but
> it's finally faster than checking via division on my machine:
> ...

If you've actually got the energy to time these things <wink>, how about
adapting the int-mul overflow checking code in Python's intobject.c's
int_mul() function too?  The CVS (ditto 2.2.2) version

+ does rely on floating point

+ doesn't use division

+ does work for signed integral types

+ doesn't assume that the number of mantissa bits in a double
  is enough to hold a full-precision integral product

+ does assume that the largest integral product is within the
  dynamic range of a double

It could be simplified a little if it were specialized to unsigned mult.