open Optimize_local
open Opt_tmp
open Syntax

let remove_case_with_only_default = function
    Case (s, [], st) -> st
  | a -> a

let rec create_or_cond_from_list s = function
    [] -> []
  | i::il -> (Equals(s, i)::create_or_cond_from_list s il)

let rec create_elseif_list_from_arm_list s = function
    [] -> []
  | Arm([],st)::r -> create_elseif_list_from_arm_list s r
	(* I remove this switch because it cannot be called 
	   This should never occur because such arms were 
	   already removed *)
  | Arm(il,st)::r -> (Elseif(Or(create_or_cond_from_list s il), st)::create_elseif_list_from_arm_list s r)

let rec remove_useless_arms = function
    [] -> []
  | Arm([], st)::r -> remove_useless_arms r
  | h::t -> (h::remove_useless_arms t)

let rec remove_case_with_many_arm = function
  | Case (s, [], st) -> st
  | Case (s, Arm([], st)::al, dst) -> remove_case_with_many_arm (Case(s, al, dst))
	(* this switch is removed because it can never be called *)
  | Case (s, Arm(il,st)::al, dst) -> (
      let al' = remove_useless_arms al in
      let ocst =  Case (s, Arm(il,st)::al', dst) in
      let newst = If(Or (create_or_cond_from_list s il), st, create_elseif_list_from_arm_list s al', dst) in
      if (Cout.cout_mem_st newst) < (Cout.cout_mem_st ocst)
      then newst
      else ocst
     )
  | a -> a