CristalCaveGem » LustreC

  | MLocalAssign (_, { value_desc = Cst (Const_tag c); _ })

let machine_fusion m =

  let m = { m with mstep = step_fusion m.mstep } in

  let unused = Machine_code_dep.compute_unused_variables m in

  let is_used v = not (ISet.mem v.var_id unused) in

  let step_locals = List.filter is_used m.mstep.step_locals in

  let rec filter_instrs instrs =

    List.filter_map (fun instr -> match get_instr_desc instr with

        | MLocalAssign (v, _) ->

          if is_used v then Some instr else None

        | MBranch (e, hl) ->

          Some (update_instr_desc instr

                  (MBranch (e, List.map (fun (h, l) -> h, filter_instrs l) hl)))

        | _ -> Some instr) instrs

  in

  let step_instrs = filter_instrs m.mstep.step_instrs in

  { m with mstep = { m.mstep with step_locals; step_instrs }}

  (* List.iter (fun (g, u) -> Format.printf "%a@;%a@." pp_dep_graph g ISet.pp u) gs; *)

      let machine_code = machines_fusion (machines_reuse_variables reuse_tables machine_code) in

      machine_code)