Dominator symbols (was ocaml-flambda/ocaml#556) (oxcaml#143)

Author: chambart

middle_end/flambda2/compare/compare.ml

@@ -364,9 +364,9 @@ and subst_static_consts env (g : Static_const.Group.t) =
   Static_const.Group.map g ~f:(subst_static_const env)
 and subst_bindable_let_bound env (blb : Bindable_let_bound.t) =
   match blb with
-  | Symbols { bound_symbols; scoping_rule } ->
+  | Symbols { bound_symbols } ->
     let bound_symbols = subst_bound_symbols env bound_symbols in
-    Bindable_let_bound.symbols bound_symbols scoping_rule
+    Bindable_let_bound.symbols bound_symbols
   | _ ->
     blb
 and subst_bound_symbols env bound_symbols =
@@ -1220,14 +1220,6 @@ and let_symbol_exprs env
   ((bound_symbols2 : Bindable_let_bound.symbols), static_consts2, body2)
     : Expr.t Comparison.t =
   let ok = ref true in
-  let scoping_rule1 = bound_symbols1.scoping_rule in
-  let scoping_rule2 = bound_symbols2.scoping_rule in
-  begin
-    match scoping_rule1, scoping_rule2 with
-    | Syntactic, Syntactic
-    | Dominator, Dominator -> ()
-    | _, _ -> ok := false
-  end;
   let bound_symbols1 = bound_symbols1.bound_symbols in
   let bound_symbols2 = bound_symbols2.bound_symbols in
   let bound_symbols1' : Bound_symbols.t =
@@ -1251,7 +1243,7 @@ and let_symbol_exprs env
     else
       let approximant =
         Let.create
-          (Bindable_let_bound.symbols bound_symbols1' scoping_rule1)
+          (Bindable_let_bound.symbols bound_symbols1')
           (Named.create_static_consts static_consts1')
           ~body:body1'
           ~free_names_of_body:Unknown

middle_end/flambda2/from_lambda/closure_conversion.ml

@@ -1111,7 +1111,7 @@ let close_program ~backend ~module_ident ~module_block_size_in_words
           (Static_const.Group.create [static_const])
       in
       Let_with_acc.create acc
-        (Bindable_let_bound.symbols bound_symbols Syntactic)
+        (Bindable_let_bound.symbols bound_symbols)
         named
         ~body:return
         ~free_names_of_body:Unknown
@@ -1178,7 +1178,7 @@ let close_program ~backend ~module_ident ~module_block_size_in_words
           |> Named.create_static_consts
         in
         Let_with_acc.create acc
-          (Bindable_let_bound.symbols bound_symbols Syntactic)
+          (Bindable_let_bound.symbols bound_symbols)
           defining_expr ~body ~free_names_of_body:Unknown
         |> Expr_with_acc.create_let)
       (Acc.code acc)
@@ -1209,7 +1209,7 @@ let close_program ~backend ~module_ident ~module_block_size_in_words
         |> Named.create_static_consts
       in
       Let_with_acc.create acc
-        (Bindable_let_bound.symbols bound_symbols Syntactic)
+        (Bindable_let_bound.symbols bound_symbols)
         defining_expr ~body ~free_names_of_body:Unknown
       |> Expr_with_acc.create_let)
       (acc, body)

middle_end/flambda2/inlining/call_site_inlining_decision.ml

@@ -214,8 +214,18 @@ let speculative_inlining dacc ~apply ~function_decl ~simplify_expr
         | Never_returns -> Continuation.create ()
         | Return cont -> cont
       in
-      let { required_variables; } : Data_flow.result =
+      (* When doing the speculative analysis, in order to not blow up,
+         the data_flow analysis is only done on the speculatively inlined
+         body; however the reachable code_ids part of the data flow analysis
+         is only correct at toplevel when all information about the
+         code_age relation and used_closure vars is available (for the whole
+         compilation unit). Thus we here provide empty/dummy values
+         for the used_closure_vars and code_age_relation, and ignore the
+         reachable_code_id part of the data_flow analysis. *)
+      let { required_names; reachable_code_ids = _; } : Data_flow.result =
         Data_flow.analyze data_flow
+          ~code_age_relation:Code_age_relation.empty
+          ~used_closure_vars:Unknown
           ~return_continuation:function_return_cont
           ~exn_continuation:(Exn_continuation.exn_handler exn_continuation)
       in
@@ -227,7 +237,7 @@ let speculative_inlining dacc ~apply ~function_decl ~simplify_expr
           UE.add_return_continuation uenv return_continuation scope
             return_arity
       in
-      let uacc = UA.create ~required_variables uenv dacc in
+      let uacc = UA.create ~required_names ~reachable_code_ids:Unknown uenv dacc in
       rebuild uacc ~after_rebuild:(fun expr uacc -> expr, uacc)
     )
   in

middle_end/flambda2/naming/bindable_let_bound.ml

@@ -16,7 +16,6 @@
 
 type symbols = {
   bound_symbols : Bound_symbols.t;
-  scoping_rule : Symbol_scoping_rule.t;
 }
 
 type t =
@@ -40,13 +39,11 @@ include Container_types.Make (struct
         (Format.pp_print_list ~pp_sep:Format.pp_print_space
           Var_in_binding_pos.print)
         closure_vars
-    | Symbols { bound_symbols; scoping_rule; } ->
+    | Symbols { bound_symbols } ->
       Format.fprintf ppf "@[<hov 1>\
-          @[(bound_symbols@ %a)@]@ \
-          @[(scoping_rule@ %a)@]\
+          @[(bound_symbols@ %a)@]\
           )@]"
         Bound_symbols.print bound_symbols
-        Symbol_scoping_rule.print scoping_rule
 
   (* The following would only be required if using
      [Name_abstraction.Make_map], which we don't with this module. *)
@@ -78,7 +75,7 @@ let free_names t =
           Name_mode.normal)
       Name_occurrences.empty
       closure_vars
-  | Symbols { bound_symbols; scoping_rule = _; } ->
+  | Symbols { bound_symbols; } ->
     Bound_symbols.free_names bound_symbols
 
 let rec map_sharing f l0 =
@@ -103,12 +100,12 @@ let apply_renaming t perm =
     in
     if closure_vars == closure_vars' then t
     else Set_of_closures { name_mode; closure_vars = closure_vars'; }
-  | Symbols { bound_symbols; scoping_rule; } ->
+  | Symbols { bound_symbols; } ->
     let bound_symbols' =
       Bound_symbols.apply_renaming bound_symbols perm
     in
     if bound_symbols == bound_symbols' then t
-    else Symbols { scoping_rule; bound_symbols = bound_symbols'; }
+    else Symbols { bound_symbols = bound_symbols'; }
 
 let all_ids_for_export t =
   match t with
@@ -120,7 +117,7 @@ let all_ids_for_export t =
         Ids_for_export.add_variable ids (Var_in_binding_pos.var var))
       Ids_for_export.empty
       closure_vars
-  | Symbols { bound_symbols; scoping_rule = _; } ->
+  | Symbols { bound_symbols; } ->
     Bound_symbols.all_ids_for_export bound_symbols
 
 let rename t =
@@ -194,8 +191,8 @@ let set_of_closures ~closure_vars =
         Var_in_binding_pos.print)
       closure_vars
 
-let symbols bound_symbols scoping_rule =
-  Symbols { bound_symbols; scoping_rule; }
+let symbols bound_symbols =
+  Symbols { bound_symbols; }
 
 let name_mode t =
   match t with
@@ -260,8 +257,3 @@ let all_bound_vars' t =
   | Set_of_closures { closure_vars; _ } ->
     Variable.Set.of_list (List.map Var_in_binding_pos.var closure_vars)
   | Symbols _ -> Variable.Set.empty
-
-let let_symbol_scoping_rule t =
-  match t with
-  | Singleton _ | Set_of_closures _ -> None
-  | Symbols { scoping_rule; _ } -> Some scoping_rule

middle_end/flambda2/naming/bindable_let_bound.mli

@@ -18,7 +18,6 @@
 
 type symbols = private {
   bound_symbols : Bound_symbols.t;
-  scoping_rule : Symbol_scoping_rule.t;
 }
 
 type t = private
@@ -43,7 +42,7 @@ val singleton : Var_in_binding_pos.t -> t
 
 val set_of_closures : closure_vars:Var_in_binding_pos.t list -> t
 
-val symbols : Bound_symbols.t -> Symbol_scoping_rule.t -> t
+val symbols : Bound_symbols.t -> t
 
 val must_be_singleton : t -> Var_in_binding_pos.t
 
@@ -71,5 +70,3 @@ val fold_all_bound_vars
 val all_bound_vars : t -> Var_in_binding_pos.Set.t
 
 val all_bound_vars' : t -> Variable.Set.t
-
-val let_symbol_scoping_rule : t -> Symbol_scoping_rule.t option

middle_end/flambda2/parser/fexpr.ml

@@ -347,10 +347,6 @@ type apply_cont = {
   args : simple list;
 }
 
-type symbol_scoping_rule = Symbol_scoping_rule.t =
-  | Syntactic
-  | Dominator
-
 type expr =
   | Let of let_
   | Let_cont of let_cont
@@ -409,7 +405,6 @@ and let_symbol = {
   bindings : symbol_binding list;
   (* Only used if there's no [Set_of_closures] in the list *)
   closure_elements : closure_elements option;
-  scoping_rule : symbol_scoping_rule option;
   body : expr;
 }
 

middle_end/flambda2/parser/fexpr_to_flambda.ml

@@ -656,7 +656,7 @@ let rec expr env (e : Fexpr.expr) : Flambda.Expr.t =
         ~scrutinee:(simple env scrutinee)
         ~arms)
 
-  | Let_symbol { bindings; closure_elements; scoping_rule; body } ->
+  | Let_symbol { bindings; closure_elements; body } ->
     (* Desugar the abbreviated form for a single set of closures *)
     let found_explicit_set = ref false in
     let closures_in_implicit_set =
@@ -866,9 +866,8 @@ let rec expr env (e : Fexpr.expr) : Flambda.Expr.t =
       List.map (static_const env) bindings
       |> Flambda.Static_const.Group.create
     in
-    let scoping_rule = scoping_rule |> Option.value ~default:Fexpr.Syntactic in
     let body = expr env body in
-    Flambda.Let.create (Bindable_let_bound.symbols bound_symbols scoping_rule)
+    Flambda.Let.create (Bindable_let_bound.symbols bound_symbols)
       (Flambda.Named.create_static_consts static_consts)
       ~body
       ~free_names_of_body:Unknown