[llvm-dev] [New Backend] How to describe call / return instruction

[Codetector via llvm-dev]

I am currently working on a backend for a custom ISA. I am currently 
having trouble describing the call and return instruction. Specifically 
how to make the FrameInfo understand that call/ret will push/pop the 
return address off the stack. (Aka stack offset) It's currently using 
the Return Address slot as the first argument that it can not fit in 
register passing.

Any help is appreciated.