If you had money to place for a bounty, what would you choose?

[Jacob Carlborg]

On 2013-12-04 12:43, Michel Fortin wrote:

> The pointer magic for NSNumber is pretty much inconsequential: it just
> means you need to use the runtime functions everywhere, such as
> objc_getClass to get a pointer to the class object instead of
> dereferencing the object yourself. But it's a detail to keep in mind.
>
> A big change in the modern runtime is that classes are completely
> non-fragile, in that you can add a member in a superclass without
> breaking binary compatibility with derived classes. Which means that
> instance variables are accessed differently, by checking a global
> constant to find the right offset (initialized when first loading the
> class). I think the compiler also has to emit that constant that the
> runtime will initialize.
>
> Another big change is exception handling which now piggyback on the C++
> exception mechanism instead of using the inefficient longjump
> implementation of the previous runtime.
>
> There's an optimized path for calling certain methods using a virtual
> table, but we can skip that in a first release as it's an optimisation
> (objc_msgSend still work fine in every case).
>
> Beside that, they changed all the section names for the binary output,
> and probably did a some alterations to the binary structure I'm
> forgetting right now.

What I actually was asking is if there's any difference in the 32bit 
modern runtime as used by iOS and the 64bit modern runtime? Except for 
the usual differences that exists in C.

-- 
/Jacob Carlborg