fixup! Effects: partial CPS transform

Author: vouillon

compiler/lib/global_flow.ml

@@ -25,7 +25,7 @@ blocks, to track functions across modules.
 
 open! Stdlib
 
-let debug = Debug.find "flow2"
+let debug = Debug.find "global-flow"
 
 let times = Debug.find "times"
 
@@ -133,11 +133,9 @@ let rec arg_deps st ?ignore params args =
   | x :: params, y :: args ->
       (* This is to deal with the [else] clause of a conditional,
          where we know that the value of the tested variable is 0. *)
-      if not
-           (match ignore with
-           | Some y' -> Var.equal y y'
-           | _ -> false)
-      then add_assign_def st x y;
+      (match ignore with
+      | Some y' when Var.equal y y' -> ()
+      | _ -> add_assign_def st x y);
       arg_deps st params args
   | _ -> ()
 
@@ -263,16 +261,17 @@ let program_deps st { blocks; _ } =
           cont_deps blocks st cont)
     blocks
 
-(* For each variable, we keep track of which values (function or
-   block) if may contain. We loose a lot of information when going to
-   [Top] since we have to assume that all functions might escape. So,
-   having possibly unknown values does not move us to [Top]; we use a
-   flag for that instead. *)
+(* For each variable, we keep track of which values, function or
+   block, it may contain. Other kinds of values are not relevant and
+   just ignored. We loose a lot of information when going to [Top]
+   since we have to assume that all functions might escape. So, having
+   possibly unknown values does not move us to [Top]; we use a flag
+   for that instead. *)
 type approx =
   | Top
   | Values of
-      { known : Var.Set.t (* List of possible values *)
-      ; others : bool (* Whether other values are possible *)
+      { known : Var.Set.t (* List of possible values (functions and blocks) *)
+      ; others : bool (* Whether other functions or blocks are possible *)
       }
 
 module Domain = struct
@@ -566,7 +565,7 @@ let f p =
     Var.ISet.iter
       (fun x ->
         let s = Var.Tbl.get approximation x in
-        if true || not (Poly.( = ) s Domain.bot)
+        if not (Domain.equal s Domain.bot)
         then
           Format.eprintf
             "%a: %a@."