diff options
author | Son Ho | 2022-12-17 12:54:53 +0100 |
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committer | Son HO | 2023-02-03 11:21:46 +0100 |
commit | 01a95c7da8cc0c937d94e6a9bc753d2ceb163c17 (patch) | |
tree | 4f5c21c393829e5192c13d5eb272a28dc9f97d9e | |
parent | e92d5bc74fe735717bfd8ec65c70335831bf85da (diff) |
Implement a micro-pass to simplify the let-bindings followed by a return
Diffstat (limited to '')
-rw-r--r-- | compiler/Config.ml | 2 | ||||
-rw-r--r-- | compiler/Interpreter.ml | 2 | ||||
-rw-r--r-- | compiler/PureMicroPasses.ml | 63 | ||||
-rw-r--r-- | compiler/PureUtils.ml | 36 |
4 files changed, 101 insertions, 2 deletions
diff --git a/compiler/Config.ml b/compiler/Config.ml index b37d4a84..0b8ee574 100644 --- a/compiler/Config.ml +++ b/compiler/Config.ml @@ -266,7 +266,7 @@ let unfold_monadic_let_bindings = ref false we later filter the useless *forward* calls in the micro-passes, where it is more natural to do. - See the comments for {!PureMicroPasses.expression_contains_child_call_in_all_paths} + See the comments for {!Aeneas.PureMicroPasses.expression_contains_child_call_in_all_paths} for additional explanations. *) let filter_useless_monadic_calls = ref true diff --git a/compiler/Interpreter.ml b/compiler/Interpreter.ml index 69109c4e..dd0051f6 100644 --- a/compiler/Interpreter.ml +++ b/compiler/Interpreter.ml @@ -126,7 +126,7 @@ let initialize_symbolic_context_for_fun (type_context : C.type_context) the synthesis (mostly by ending abstractions). [is_regular_return]: [true] if we reached a [Return] instruction (i.e., the - result is {!Return} or {LoopReturn}). + result is {!Return} or {!LoopReturn}). [inside_loop]: [true] if we are *inside* a loop (result [EndContinue]). *) diff --git a/compiler/PureMicroPasses.ml b/compiler/PureMicroPasses.ml index 937c9103..3937db0a 100644 --- a/compiler/PureMicroPasses.ml +++ b/compiler/PureMicroPasses.ml @@ -885,6 +885,53 @@ let filter_useless (filter_monadic_calls : bool) (ctx : trans_ctx) let body = { body with body = body_exp; inputs_lvs } in { def with body = Some body } +(** Simplify the lets immediately followed by a return. + + Ex.: + {[ + x <-- f y; + Return x + + ~~> + + f y + ]} + *) +let simplify_let_then_return _ctx def = + let expr_visitor = + object (self) + inherit [_] map_expression + + method! visit_Let env monadic lv rv next_e = + (* We do a bottom up traversal (simplifying in the children nodes + can allow to simplify in the parent nodes) *) + let rv = self#visit_texpression env rv in + let next_e = self#visit_texpression env next_e in + let not_simpl_e = Let (monadic, lv, rv, next_e) in + match next_e.e with + | Switch _ | Loop _ | Let _ -> + (* Small shortcut to avoid doing the check on every let-binding *) + not_simpl_e + | _ -> ( + match typed_pattern_to_texpression lv with + | None -> not_simpl_e + | Some lv_v -> + let lv_v = + if monadic then mk_result_return_texpression lv_v else lv_v + in + if lv_v = next_e then rv.e else not_simpl_e) + end + in + + match def.body with + | None -> def + | Some body -> + (* Visit the body *) + let body_exp = expr_visitor#visit_texpression () body.body in + (* Return *) + let body = { body with body = body_exp } in + { def with body = Some body } + (** Simplify the aggregated ADTs. Ex.: {[ @@ -1513,6 +1560,22 @@ let apply_end_passes_to_def (ctx : trans_ctx) (def : fun_decl) : fun_decl = let def = filter_useless !Config.filter_useless_monadic_calls ctx def in log#ldebug (lazy ("filter_useless:\n\n" ^ fun_decl_to_string ctx def ^ "\n")); + (* Simplify the lets immediately followed by a return. + + Ex.: + {[ + x <-- f y; + Return x + + ~~> + + f y + ]} + *) + let def = simplify_let_then_return ctx def in + log#ldebug + (lazy ("simplify_let_then_return:\n\n" ^ fun_decl_to_string ctx def ^ "\n")); + (* Simplify the aggregated ADTs. Ex.: diff --git a/compiler/PureUtils.ml b/compiler/PureUtils.ml index e1421f5a..4816f31f 100644 --- a/compiler/PureUtils.ml +++ b/compiler/PureUtils.ml @@ -155,6 +155,11 @@ let is_global (e : texpression) : bool = let is_const (e : texpression) : bool = match e.e with Const _ -> true | _ -> false +let ty_as_adt (ty : ty) : type_id * ty list = + match ty with + | Adt (id, tys) -> (id, tys) + | _ -> raise (Failure "Unreachable") + (** Remove the external occurrences of {!Meta} *) let rec unmeta (e : texpression) : texpression = match e.e with Meta (_, e) -> unmeta e | _ -> e @@ -473,3 +478,34 @@ let mk_fuel_var (id : VarId.id) : var = let mk_fuel_texpression (id : VarId.id) : texpression = { e = Var id; ty = mk_fuel_ty } + +let rec typed_pattern_to_texpression (pat : typed_pattern) : texpression option + = + let e_opt = + match pat.value with + | PatConstant pv -> Some (Const pv) + | PatVar (v, _) -> Some (Var v.id) + | PatDummy -> None + | PatAdt av -> + let fields = List.map typed_pattern_to_texpression av.field_values in + if List.mem None fields then None + else + let fields_values = List.map (fun e -> Option.get e) fields in + + (* Retrieve the type id and the type args from the pat type (simpler this way *) + let adt_id, type_args = ty_as_adt pat.ty in + + (* Create the constructor *) + let qualif_id = AdtCons { adt_id; variant_id = av.variant_id } in + let qualif = { id = qualif_id; type_args } in + let cons_e = Qualif qualif in + let field_tys = + List.map (fun (v : texpression) -> v.ty) fields_values + in + let cons_ty = mk_arrows field_tys pat.ty in + let cons = { e = cons_e; ty = cons_ty } in + + (* Apply the constructor *) + Some (mk_apps cons fields_values).e + in + match e_opt with None -> None | Some e -> Some { e; ty = pat.ty } |