On Saturday 13 July 2024 22:38:42 GMT-7 zxuiji wrote:
> By making pointers exclusive to compile time and not part of the stdabi it
> becomes possible to unify the abi that is linked (for example linking x86
> apps to an x86_64 library directly). This is the very thing I'm doing in my
> own library launcher pair. I did not realise until reading it in this chain
> however that there are differences in calling conventions between the GNUC
> family of compilers. For now I've tacked __cdecl onto my global API define
> but will need something to address that 16byte aligned vs 4 byte aliigned
> thing I read on wikipedia

The registers being used are also different. You can't call a 64-bit function
from 32-bit (unless you can figure out how to access r8 and r9 in 32-bit code).
It's also not as clearly obvious, but you can't call 32-bit code from 64-bit
easily either, because the "push" instruction in 64-bit writes 64 bits to the
stack.

Given you can't call such functions across ABI boundaries at all, what's the
point of erasing the pointer size? And besides, how big a pointer is big
enough?

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
  Principal Engineer - Intel DCAI Platform & System Engineering