1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
open RTL
open Maps
open Camlcoq
open Registers
open Kildall
open Lattice
let p2i r = P.to_int r
let get_some = function
| None -> failwith "Got None instead of Some _"
| Some thing -> thing
let successors_inst = function
| Inop n
| Iop (_, _, _, n)
| Iload (_, _, _, _, _, n)
| Istore (_, _, _, _, n)
| Icall (_, _, _, _, n)
| Ibuiltin (_, _, _, n) ->
[ n ]
| Icond (_, _, n1, n2, _) -> [ n1; n2 ]
| Ijumptable (_, l) -> l
| Itailcall _ | Ireturn _ -> []
let predicted_successor = function
| Inop n | Iop (_, _, _, n) | Iload (_, _, _, _, _, n) | Istore (_, _, _, _, n)
->
Some n
| Icall (_, _, _, _, n) | Ibuiltin (_, _, _, n) -> None
| Icond (_, _, n1, n2, p) -> (
match p with Some true -> Some n1 | Some false -> Some n2 | None -> None)
| Ijumptable _ | Itailcall _ | Ireturn _ -> None
let non_predicted_successors i = function
| None -> successors_inst i
| Some ps -> List.filter (fun s -> s != ps) (successors_inst i)
(* adapted from Linearizeaux.get_join_points *)
let get_join_points code entry =
let reached = ref (PTree.map (fun n i -> false) code) in
let reached_twice = ref (PTree.map (fun n i -> false) code) in
let rec traverse pc =
if get_some @@ PTree.get pc !reached then begin
if not (get_some @@ PTree.get pc !reached_twice) then
reached_twice := PTree.set pc true !reached_twice
end else begin
reached := PTree.set pc true !reached;
traverse_succs (successors_inst @@ get_some @@ PTree.get pc code)
end
and traverse_succs = function
| [] -> ()
| [pc] -> traverse pc
| pc :: l -> traverse pc; traverse_succs l
in traverse entry; !reached_twice
let transfer f pc after = let open Liveness in
match PTree.get pc f.fn_code with
| Some i ->
(match i with
| Inop _ -> after
| Iop (_, args, res, _) ->
reg_list_live args (Regset.remove res after)
| Iload (_, _, _, args, dst, _) ->
reg_list_live args (Regset.remove dst after)
| Istore (_, _, args, src, _) ->
reg_list_live args (Regset.add src after)
| Icall (_, ros, args, res, _) ->
reg_list_live args (reg_sum_live ros (Regset.remove res after))
| Itailcall (_, ros, args) ->
reg_list_live args (reg_sum_live ros Regset.empty)
| Ibuiltin (_, args, res, _) ->
reg_list_live (AST.params_of_builtin_args args)
(reg_list_dead (AST.params_of_builtin_res res) after)
| Icond (_, args, _, _, _) ->
reg_list_live args after
| Ijumptable (arg, _) ->
Regset.add arg after
| Ireturn optarg ->
reg_option_live optarg Regset.empty)
| None -> Regset.empty
module RegsetLat = LFSet(Regset)
module DS = Backward_Dataflow_Solver(RegsetLat)(NodeSetBackward)
let analyze f =
let liveouts = get_some @@ DS.fixpoint f.fn_code successors_instr (transfer f) in
PTree.map (fun n _ -> let lo = PMap.get n liveouts in transfer f n lo) f.fn_code
|
