sr (nobody.delete@this.nowhere.com) on September 25, 2021 10:34 am wrote:
> And if divided only to code, data and stack will it complicate things at all?

Ok, let's explore this for a second...

What does a call to, say, memmove() look like at the ABI level?

Does the code have to test to see whether either src and dst are stack or data pointers?

Or, worse, are there 4 versions of memmove() for the data/data, data/stack, stack/data, and stack/stack variants? How would this scale if you had many segments (say, one per mmap'd object or something)?

If not, how do you pass these universal pointers? Are they 'fat' 80 or 128 bit objects? Or, are the segment bits stuck somewhere in the high bits of a normal-sized pointer, or do segments burn another argument slot (either as registers or on the call stack), so memmove() would take 5 args rather than 3?

Now, once you've selected your point in the design space, just one more question - what do you get for it? Yes, data/stack is just one bit and probably easy to stick somewhere, but it's also one of the least interesting splits once you're beyond the memory/transistor budgets of the early-80's.

-JohnG