(** Shifting stack-relative references.  This is used in [Stacking]. *)
Definition shift_stack_addressing (delta: Z) (addr: addressing) :=
match addr with
| Ainstack ofs => Ainstack (Ptrofs.add ofs (Ptrofs.repr delta))
| _ => addr
end.
Definition shift_stack_operation (delta: Z) (op: operation) :=
match op with
| Oaddrstack ofs => Oaddrstack (Ptrofs.add ofs (Ptrofs.repr delta))
| _ => op
end.

Lemma type_shift_stack_addressing:
forall delta addr, type_of_addressing (shift_stack_addressing delta addr) = type_of_addressing addr.