Yeah it’s the drawback, originally it used segmented stacks but that has its own issues.
And it’s probably not the worst issue because deep stacks and stack pointers will mostly be relevant for long running routines which will stabilise their stack use after a while (even if some are likely subject to threshold effects if they’re at the edge, I would not be surprised if some codebases ballasted stacks ahead of time). Also because stack pointers will get promoted to the heap if they escape so the number of stack pointers is not unlimited, and the pointer has to live downwards on the stack.
cperciva|1 year ago
I guess if you're already doing garbage collection moving the stack doesn't make things all that much worse though... still, yuck.
masklinn|1 year ago
And it’s probably not the worst issue because deep stacks and stack pointers will mostly be relevant for long running routines which will stabilise their stack use after a while (even if some are likely subject to threshold effects if they’re at the edge, I would not be surprised if some codebases ballasted stacks ahead of time). Also because stack pointers will get promoted to the heap if they escape so the number of stack pointers is not unlimited, and the pointer has to live downwards on the stack.