According to Orlando Llanes:
Is there a way to specify to GPC, or for GPC to specify to AS, to
reference Object fields (variables) using the stack rather than registers?
Object fields are stored in memory - usually on the heap - and not in registers. Perhaps you are referring to parameter passing, especially passing the implicit `Self' parameter through the stack rather than a register? Normally, GPC should behave according to your needs.
What about the following: Write a dummy for your asm routine in a Pascal unit and compile it with -S, so you can see how GPC passes the parameters and can do it in a similar - but of course much better ;-) way.
Hope this helps,
Peter