first version of clock unification

This commit is contained in:
Antoine Grimod 2023-01-09 20:57:19 +01:00
parent 68d67bb53b
commit ad97c6b627
4 changed files with 124 additions and 85 deletions

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@ -77,3 +77,4 @@ type t_ck = base_ck list
and base_ck =
| Base
| On of base_ck * t_expression
| Unknown

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@ -25,8 +25,6 @@ let exec_passes ast verbose debug passes f =
| [] -> f ast
| (n, p) :: passes ->
verbose (Format.asprintf "Executing pass %s:\n" n);
try
begin
match p verbose debug ast with
| None -> (exit_error ("Error while in the pass "^n^".\n"); exit 0)
| Some ast -> (
@ -34,8 +32,6 @@ let exec_passes ast verbose debug passes f =
(Format.asprintf
"Current AST (after %s):\n%a\n" n Lustre_pp.pp_ast ast);
aux ast passes)
end with
| _ -> failwith ("The pass "^n^" should have caught me!")
in
aux ast passes
@ -47,7 +43,7 @@ let _ =
["linearization_reset"; "automata_translation"; "remove_if";
"linearization_pre"; "linearization_tuples"; "linearization_app";
"ensure_assign_val";
"equations_ordering"] in
"equations_ordering"; "clock_unification"] in
let sanity_passes = ["sanity_pass_assignment_unicity"; "check_typing"] in
let usage_msg =
"Usage: main [-passes p1,...,pn] [-ast] [-verbose] [-debug] \

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@ -933,101 +933,137 @@ let clock_unification_pass verbose debug ast =
let failure str = raise (PassExn ("Failed to unify clocks: "^str)) in
let known_clocks = Hashtbl.create 100 in
let used = Hashtbl.create 100 in (*keep track of variables that appear on right side of equation*)
let changed = ref false in
let find_clock_var var =
match Hashtbl.find_opt known_clocks var with
| None ->
begin
match var with
| BVar(name)
| IVar(name)
| RVar(name) -> raise (PassExn ("Cannot find clock of variable "^name) )
end
| Some c -> c
let rec count_not e acc = match e with
| EVar([TBool], var) -> acc, e
| EConst([TBool], cons) -> acc, e
| EMonOp([TBool], MOp_not, e) -> count_not e (acc + 1)
| _ -> raise (PassExn "verify_when failure")
in
let rec compute_clock_exp exp = match exp with
| EConst(_, _) -> [Base]
| EVar(_, var) -> find_clock_var var
| EMonOp(_, MOp_pre, _) -> [Base]
| EMonOp(_, _, e) -> compute_clock_exp e
let verify_when e1 e2 =
let n1, var1 = count_not e1 0
and n2, var2 = count_not e2 0 in
if n1 mod 2 <> n2 mod 2 || var1 <> var2 then
raise (PassExn "clock unification failure")
in
let get_var_name var = match var with
| RVar(name)
| BVar(name)
| IVar(name) -> name
in
let rec clk_to_string clk = match clk with
| Base -> "Base"
| Unknown -> "Unknown"
| On(clk, exp) ->
let n, var = count_not exp 0 in
let s = if n mod 2 = 1 then "not " else "" in
let v = match var with |EVar(_, var) -> get_var_name var | EConst(_, CBool(false)) -> "false" |_ -> "true" in
(clk_to_string clk) ^ " on " ^ s ^ v
in
let add_clock var clock =
match Hashtbl.find known_clocks var with
| Unknown -> changed := true; (debug ("Found clock for "^(get_var_name var)^": "^(clk_to_string clock))); Hashtbl.replace known_clocks var clock
| c when c = clock -> ()
| c -> raise (PassExn ("Clock conflict "^(get_var_name var) ^" "^(clk_to_string c) ^ " " ^ (clk_to_string clock)))
in
let rec update_clock exp clk = match exp with
| EConst(_, _) -> ()
| EVar(_, var) -> add_clock var clk; Hashtbl.replace used var var
| EMonOp(_, _, e) -> update_clock e clk
| EComp(_, _, e1, e2)
| EReset(_, e1, e2)
| EBinOp(_, _, e1, e2) ->
begin
let c1 = compute_clock_exp e1
and c2 = compute_clock_exp e2 in
if c1 <> c2 then
failure "Binop"
else
c1
end
| EWhen(_, e1, e2) ->
begin
match compute_clock_exp e1 with
| [c1] -> [On (c1, e2)]
| _ -> failure "When"
end
| EBinOp(_, _, e1, e2) -> update_clock e1 clk; update_clock e2 clk
| ETriOp(_, TOp_merge, e1, e2, e3) ->
begin
let c1 = compute_clock_exp e1
and c2 = compute_clock_exp e2
and c3 = compute_clock_exp e3 in
match c1, c2, c3 with
| [c1], [On(cl2, e2)], [On(cl3, e3)] ->
begin
if cl2 <> c1 || cl3 <> c1 then
failure "Triop clocks"
else match e2, e3 with
| EMonOp(_, MOp_not, e), _ when e = e3 -> [c1]
| _, EMonOp(_, MOp_not, e) when e = e2 -> [c1]
| _ -> failure "Triop condition"
end
| _ -> failure ("Merge format")
end
update_clock e1 clk;
update_clock e2 (On(clk, e1));
update_clock e3 (On(clk, EMonOp([TBool], MOp_not, e1)))
| ETriOp(_, TOp_if, e1, e2, e3) ->
let (* Unused: c1 = compute_clock_exp e1
and*) c2 = compute_clock_exp e2
and c3 = compute_clock_exp e3 in
if c2 <> c3 then
failure "If clocks"
else c2
| ETuple(_, explist) -> List.concat_map compute_clock_exp explist
| EApp(_, node, e) ->
let rec aux_app clk_list = match clk_list with
| [] -> raise (PassExn "Node called with no argument provided")
| [cl] -> cl
| t::q -> if t = (aux_app q) then t else failure "App diff clocks"
and mult_clk cl out_list = match out_list with
| [] -> []
| t::q -> cl::(mult_clk cl q)
in
mult_clk (aux_app (compute_clock_exp e)) (snd node.n_outputs)
(* The 3 expressions should have the same clock *)
begin
update_clock e1 clk;
update_clock e2 clk;
update_clock e3 clk
end
| ETuple(_, explist) -> List.iter (fun e -> update_clock e clk) explist
| EApp(_, node, e) -> update_clock e clk
| EWhen(_, e1, e2) ->
match clk with
| On(clk2, e) -> verify_when e e2; update_clock e1 clk2
| _ -> raise (PassExn "Clock unification failure: when")
in
let rec compute_eq_clock eq =
let rec step vars clks = match vars, clks with
| [], [] -> ()
| [], c::q -> raise (PassExn "Mismatch between clock size")
| v::t, c::q -> Hashtbl.replace known_clocks v [c]; step t q
| l, [] -> raise (PassExn "Mismatch between clock size")
let rec propagate_clock eqs =
let rec step ((ty, vars), exp)= match vars with
| [] -> ()
| v::t -> let clk = Hashtbl.find known_clocks v in
begin
if clk <> Unknown then update_clock exp clk
else ();
step ((ty, t), exp)
end
in
let (_, vars), exp = eq in
let clk = compute_clock_exp exp in
step vars clk
List.iter step eqs
in
let rec iter_til_stable eqs =
changed := false;
propagate_clock eqs;
if !changed then
iter_til_stable eqs
in
let check_unification node =
let (_, node_inputs) = node.n_inputs in
let rec check_vars_aux acc = match acc with
| [(v, c)] -> if c = Unknown && (Hashtbl.mem used v) then raise (PassExn ("Clock unification failure: Unkwown clock for "^(get_var_name v))) else c
| (v, t)::q -> let c = check_vars_aux q in
if c <> t then raise (PassExn "Clock unification failure: Non homogeneous equation") else c
| [] -> raise (PassExn "Clock unification failure: empty equation")
in
let rec check_vars ((ty, vars), exp) acc = match vars with
| [] -> let _ = check_vars_aux acc in ()
| v::t -> check_vars ((ty, t), exp) ((v, Hashtbl.find known_clocks v)::acc)
in
let rec check_inputs inputs = match inputs with
| [] -> ()
| i::q -> let c = Hashtbl.find known_clocks i in
match c with
| On(_, e) -> let _, var = count_not e 0 in
begin
match var with
| EConst(_, _) -> ()
| EVar(_, var) -> if not (List.mem var node_inputs) then raise (PassExn "Clock unification failure: input clock depends on non input clock")
else check_inputs q
end
| _ -> check_inputs q
in
(*Check that all variables used have a clock
and that inputs clocks do not depend on local vars or outputs*)
List.iter (fun eq -> check_vars eq []) node.n_equations;
check_inputs node_inputs;
in
let compute_clock_node n =
begin
Hashtbl.clear known_clocks;
List.iter (fun v -> Hashtbl.replace known_clocks v [Base]) (
snd n.n_inputs); (* Initializing inputs to base clock *)
List.iter compute_eq_clock n.n_equations;
if not (List.for_all (fun v -> (Hashtbl.find known_clocks v) = [Base]) (
snd n.n_outputs)) then failure "Outputs" (*Checking that the node's output are on base clock *)
else
Some n
List.iter (fun v -> Hashtbl.replace known_clocks v Unknown) (
snd n.n_inputs); (* Initializing inputs to Unknown clock *)
List.iter (fun v -> Hashtbl.replace known_clocks v Unknown) (
snd n.n_local_vars); (* Initializing local variables to Unknown clock *)
List.iter (fun v -> Hashtbl.replace known_clocks v Base) (
snd n.n_outputs); (* Initializing outputs to base clock *)
iter_til_stable n.n_equations;
(* catch potential errors and test for unification *)
check_unification n;
Some n
end
in node_pass compute_clock_node ast

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@ -16,3 +16,9 @@ let
tmp = aux (a+b, i);
tel
node test (u, v: int; c: bool) returns (o: int);
var x, y: int; b: bool;
let
o = 2 * (merge c u v);
tel