heptagon/compiler/minils/transformations/normalize.ml
2010-07-15 09:37:20 +02:00

260 lines
9.9 KiB
OCaml

(**************************************************************************)
(* *)
(* Heptagon *)
(* *)
(* Author : Marc Pouzet *)
(* Organization : Demons, LRI, University of Paris-Sud, Orsay *)
(* *)
(**************************************************************************)
(* $Id$ *)
open Misc
open Names
open Ident
open Signature
open Minils
open Mls_utils
let ctrue = Name "true"
and cfalse = Name "false"
let equation (d_list, eq_list) ({ e_ty = te; e_ck = ck } as e) =
let n = Ident.fresh "_v" in
let d_list = (mk_var_dec ~clock:ck n te) :: d_list in
let eq_list = (mk_equation (Evarpat n) e) :: eq_list in
(d_list, eq_list), n
let intro context e =
match e.e_desc with
| Evar n -> context, n
| _ -> equation context e
(* distribution: [(e1,...,ek) when C(n) = (e1 when C(n),...,ek when C(n))] *)
let rec whenc context e c n =
let when_on_c c n e =
{ e with e_desc = Ewhen(e, c, n); e_ck = Con(e.e_ck, c, n) } in
match e.e_desc with
| Eapp({ a_op = Etuple } as app, e_list, r) ->
let context, e_list =
List.fold_right
(fun e (context, e_list) -> let context, e = whenc context e c n in
(context, e :: e_list))
e_list (context, []) in
context, { e with e_desc = Eapp (app, e_list, r);
e_ck = Con(e.e_ck, c, n) }
(* | Emerge _ -> let context, x = equation context e in
context, when_on_c c n { e with e_desc = Evar(x) } *)
| _ -> context, when_on_c c n e
(* transforms [merge x (c1, (e11,...,e1n));...;(ck, (ek1,...,ekn))] into *)
(* [merge x (c1, e11)...(ck, ek1),..., merge x (c1, e1n)...(ck, ekn)] *)
let rec merge e x ci_a_list =
let rec split ci_tas_list =
match ci_tas_list with
| [] | (_, _, []) :: _ -> [], []
| (ci, b, a :: tas) :: ci_tas_list ->
let ci_ta_list, ci_tas_list = split ci_tas_list in
(ci, a) :: ci_ta_list, (ci, b, tas) :: ci_tas_list in
let rec distribute ci_tas_list =
match ci_tas_list with
| [] | (_, _, []) :: _ -> []
| (ci, b, (eo :: _)) :: _ ->
let ci_ta_list, ci_tas_list = split ci_tas_list in
let ci_tas_list = distribute ci_tas_list in
(if b then
{ eo with e_desc = Emerge(x, ci_ta_list);
e_ck = e.e_ck; e_loc = e.e_loc }
else
merge e x ci_ta_list)
:: ci_tas_list in
let rec erasetuple ci_a_list =
match ci_a_list with
| [] -> []
| (ci, { e_desc = Eapp({ a_op = Etuple }, l, _) }) :: ci_a_list ->
(ci, false, l) :: erasetuple ci_a_list
| (ci, e) :: ci_a_list ->
(ci, true, [e]) :: erasetuple ci_a_list in
let ci_tas_list = erasetuple ci_a_list in
let ci_tas_list = distribute ci_tas_list in
match ci_tas_list with
| [e] -> e
| l -> { e with e_desc = Eapp(mk_app Etuple, l, None) }
let ifthenelse context e1 e2 e3 =
let context, n = intro context e1 in
let context, e2 = whenc context e2 ctrue n in
let context, e3 = whenc context e3 cfalse n in
context, merge e1 n [ctrue, e2; cfalse, e3]
let const e c =
let rec const = function
| Cbase | Cvar { contents = Cindex _ } -> c
| Con(ck_on, tag, x) ->
Ewhen({ e with e_desc = const ck_on; e_ck = ck_on }, tag, x)
| Cvar { contents = Clink ck } -> const ck in
const e.e_ck
(* normal form for expressions and equations: *)
(* - e ::= op(e,...,e) | x | C | e when C(x) *)
(* - act ::= e | merge x (C1 -> act) ... (Cn -> act) | (act,...,act) *)
(* - eq ::= [x = v fby e] | [pat = act ] | [pat = f(e1,...,en) every n *)
(* - A-normal form: (e1,...,en) when c(x) = (e1 when c(x),...,en when c(x) *)
type kind = VRef | Exp | Act | Any
let function_args_kind = Exp
let merge_kind = Act
let rec constant e = match e.e_desc with
| Econst _ -> true
| Ewhen(e, _, _) -> constant e
| Evar _ -> true
| _ -> false
let add context expected_kind ({ e_desc = de } as e) =
let up = match de, expected_kind with
| (Evar _ | Eapp ({ a_op = Efield }, _, _)) , VRef -> false
| _ , VRef -> true
| Eapp ({ a_op = Efun n }, _, _),
(Exp|Act) when is_op n -> false
| ( Emerge _ | Eapp _ | Efby _ ), Exp -> true
| ( Eapp({ a_op = Efun _ | Enode _ }, _, _) | Efby _ ), Act -> true
| _ -> false in
if up then
let context, n = equation context e in
context, { e with e_desc = Evar n }
else context, e
let rec translate kind context e =
let context, e = match e.e_desc with
| Emerge(n, tag_e_list) ->
let context, ta_list =
List.fold_right
(fun (tag, e) (context, ta_list) ->
let context, act = translate merge_kind context e in
context, ((tag, act) :: ta_list))
tag_e_list (context, []) in
context, merge e n ta_list
| Ewhen(e1, c, n) ->
let context, e1 = translate kind context e1 in
whenc context e1 c n
| Efby(v, e1) ->
let context, e1 = translate Exp context e1 in
let context, e1' =
if constant e1 then context, e1
else let context, n = equation context e1 in
context, { e1 with e_desc = Evar(n) } in
context, { e with e_desc = Efby(v, e1') }
| Evar _ -> context, e
| Econst c -> context, { e with e_desc = const e (Econst c) }
| Estruct(l) ->
let context, l =
List.fold_right
(fun (field, e) (context, field_desc_list) ->
let context, e = translate Exp context e in
context, ((field, e) :: field_desc_list))
l (context, []) in
context, { e with e_desc = Estruct l }
| Eapp({ a_op = Eifthenelse }, [e1; e2; e3], _) ->
let context, e1 = translate Any context e1 in
let context, e2 = translate Act context e2 in
let context, e3 = translate Act context e3 in
ifthenelse context e1 e2 e3
| Eapp(app, e_list, r) ->
let context, e_list = translate_app kind context app.a_op e_list in
context, { e with e_desc = Eapp(app, e_list, r) }
| Eiterator (it, app, n, e_list, reset) ->
let context, e_list =
translate_list function_args_kind context e_list in
context, { e with e_desc = Eiterator(it, app, n, e_list, reset) }
in add context kind e
and translate_app kind context op e_list =
match op, e_list with
| (Efun _ | Enode _), e_list ->
let context, e_list =
translate_list function_args_kind context e_list in
context, e_list
| Etuple, e_list ->
let context, e_list = translate_list kind context e_list in
context, e_list
| Efield, [e'] ->
let context, e' = translate Exp context e' in
context, [e']
| Efield_update, [e1; e2] ->
let context, e1 = translate VRef context e1 in
let context, e2 = translate Exp context e2 in
context, [e1; e2]
| Earray, e_list ->
let context, e_list = translate_list kind context e_list in
context, e_list
| Earray_fill, [e] ->
let context, e = translate VRef context e in
context, [e]
| Eselect, [e'] ->
let context, e' = translate VRef context e' in
context, [e']
| Eselect_dyn, e1::e2::idx ->
let context, e1 = translate VRef context e1 in
let context, idx = translate_list Exp context idx in
let context, e2 = translate Exp context e2 in
context, e1::e2::idx
| Eupdate, [e1; e2] ->
let context, e1 = translate VRef context e1 in
let context, e2 = translate Exp context e2 in
context, [e1; e2]
| Eselect_slice, [e'] ->
let context, e' = translate VRef context e' in
context, [e']
| Econcat, [e1; e2] ->
let context, e1 = translate VRef context e1 in
let context, e2 = translate VRef context e2 in
context, [e1; e2]
and translate_list kind context e_list =
match e_list with
[] -> context, []
| e :: e_list ->
let context, e = translate kind context e in
let context, e_list = translate_list kind context e_list in
context, e :: e_list
let rec translate_eq context eq =
(* applies distribution rules *)
(* [x = v fby e] should verifies that x is local *)
(* [(p1,...,pn) = (e1,...,en)] into [p1 = e1;...;pn = en] *)
let rec distribute ((d_list, eq_list) as context)
({ eq_lhs = pat; eq_rhs = e } as eq) =
match pat, e.e_desc with
| Evarpat(x), Efby _ when not (vd_mem x d_list) ->
let (d_list, eq_list), n = equation context e in
d_list,
{ eq with eq_rhs = { e with e_desc = Evar n } } :: eq_list
| Etuplepat(pat_list), Eapp({ a_op = Etuple }, e_list, _) ->
let eqs = List.map2 mk_equation pat_list e_list in
List.fold_left distribute context eqs
| _ -> d_list, eq :: eq_list in
let context, e = translate Any context eq.eq_rhs in
distribute context { eq with eq_rhs = e }
let translate_eq_list d_list eq_list =
List.fold_left
(fun context eq -> translate_eq context eq)
(d_list, []) eq_list
let translate_contract ({ c_eq = eq_list; c_local = d_list } as c) =
let d_list,eq_list = translate_eq_list d_list eq_list in
{ c with
c_local = d_list;
c_eq = eq_list }
let translate_node ({ n_contract = contract;
n_local = d_list; n_equs = eq_list } as node) =
let contract = optional translate_contract contract in
let d_list, eq_list = translate_eq_list d_list eq_list in
{ node with n_contract = contract; n_local = d_list; n_equs = eq_list }
let program ({ p_nodes = p_node_list } as p) =
{ p with p_nodes = List.map translate_node p_node_list }