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open Xi_lib
open Iface
open Ir
open Ir_utils
open Analysis (* <--- tu mogą być pomocne komentarze *)
open Analysis_domain
module Make() = struct
module Implementation(M:sig val cfg: ControlFlowGraph.t end) = struct
open M
(*
* Zwróćmy tablicę gdzie każdy wierzchołek jest zainicjalizowany na
* konstruktor Simple (typ BlockKnowledge) gdzie na wejściu/wyjściu
* bloku mamy pusty zbiór rejestrów.
*
* Wierzchołki oznaczające basic-bloki powinny ostatecznie być opisane
* konstruktorem Complex, ale początkowo dla wygody możemy ustawić je na Simple.
* Ważne aby funkcja przeliczająca wiedzę dla bloku podstawowego ostatecznie
* opisał blok za pomocą konstruktora Complex.
*)
let initialize_table () =
let table = Hashtbl.create 513 in
let kw = Knowledge.make ~pre:RegSet.empty ~post:RegSet.empty in
let blk_kw = BlockKnowledge.make_simple kw in
let set v =
Hashtbl.replace table v blk_kw
in
List.iter set @@ ControlFlowGraph.labels cfg;
table
let union set list=
List.fold_left (fun x y->RegSet.add y x) set list
let diff set list =
List.fold_left (fun x y->RegSet.remove y x) set list
let result : LiveVariables.table = initialize_table ()
let transfer_instr instr input =
let output = union (diff input (Ir_utils.defined_registers_instr instr)) (Ir_utils.used_registers_instr instr) in
(Knowledge.make ~pre:output ~post:input),instr
let transfer_terminator t input =
let output = union (diff input (Ir_utils.defined_registers_terminator t)) (Ir_utils.used_registers_terminator t) in
(Knowledge.make ~pre:output ~post:input),t
let rec transfer_instr_list instr input = match instr with
| [] -> [],input
| x::xs -> let ys,input = transfer_instr_list xs input in
let y= transfer_instr x input in
let output = Knowledge.pre (fst y) in
(y::ys,output)
let transfer_basic_block l current_knowledge =
if l = ControlFlowGraph.exit_label cfg then current_knowledge else
if l = ControlFlowGraph.entry_label cfg then current_knowledge else
let t = ControlFlowGraph.terminator cfg l in
let instr = ControlFlowGraph.block cfg l in
let input = BlockKnowledge.post current_knowledge in
let t_res = transfer_terminator t input in
let input2 = Knowledge.pre @@ fst t_res in
let instr_res,output = transfer_instr_list instr input2 in
let block = Knowledge.make ~pre:output ~post:input in
BlockKnowledge.make_complex ~block ~body:instr_res ~terminator:t_res
let changed = ref true
let update_in label =
let input = List.fold_left RegSet.union RegSet.empty
(List.map (fun l -> BlockKnowledge.pre (Hashtbl.find result l))
(ControlFlowGraph.successors cfg label) ) in
let old = (Hashtbl.find result label) in
let old_input = BlockKnowledge.post old in
if input=old_input then () else
changed:=true;
let new_kn = BlockKnowledge.alter_prepost ~post:input old in
Hashtbl.replace result label new_kn
let update_ins () =
let labels = ControlFlowGraph.labels cfg in
List.iter update_in labels
let update_out label =
let old = (Hashtbl.find result label) in
let old_input = BlockKnowledge.post old in
let new_kn = transfer_basic_block label old in
if new_kn=old then () else
changed:=true;
Hashtbl.replace result label new_kn
let update_outs () =
let labels = ControlFlowGraph.labels cfg in
List.iter update_out labels
let rec compute_fixpoint () =
changed := false;
update_ins ();
update_outs ();
if not !changed then () else
compute_fixpoint ()
let analyse () =
compute_fixpoint ();
result
end
let analyse cfg =
let module Instance = Implementation(struct let cfg = cfg end) in
Instance.analyse ()
end
|
