How to access the parameters on stack frame of a method

[Colin(Du Li)]

Hello,

I have a question about the cppIneterpreter, I wanna access parameters on the stack of a method.
In cppIneterpreter, when it interprets instructions "invokespecial/static/virtual", all the parameters are on the stack. But the length of each parameter is different (int is 4 bytes, double is 8 bytes...), I think I cannot access them by offset, right?
Then how can I access these parameters, especially the parameters whose types are object reference.
Thanks a lot!

Colin.