From 90dda27a3a0dce2fa2790011eff3ed3992154090 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gwena=C3=ABl=20Delaval?= <gwenael.delaval@inria.fr>
Date: Thu, 26 Jul 2012 01:29:22 +0200
Subject: [PATCH] Bug correction in Schedule_interf

Bug due to the fact that a variable can be "defined" and "read"
(in scheduling sense) by the same equation, without being a memory:
e.g., a clock defined as the result of a node application, together
with another result on this same clock.

Bug correction: basically removed the "assert false" on killed_vars,
decr_uses; do not count as "use" the self reads.
---
 compiler/minils/mls_utils.ml                  |  2 +-
 .../minils/transformations/schedule_interf.ml | 19 ++++++++++++++++---
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/compiler/minils/mls_utils.ml b/compiler/minils/mls_utils.ml
index 3af42f7..dcccee6 100644
--- a/compiler/minils/mls_utils.ml
+++ b/compiler/minils/mls_utils.ml
@@ -104,7 +104,7 @@ struct
   let def acc { eq_lhs = pat } = vars_pat acc pat
 
   let rec vars_ck acc = function
-    | Con(_, _, n) -> add n acc
+    | Con(ck, _, n) -> vars_ck (add n acc) ck
     | Cbase | Cvar { contents = Cindex _ } -> acc
     | Cvar { contents = Clink ck } -> vars_ck acc ck
 
diff --git a/compiler/minils/transformations/schedule_interf.ml b/compiler/minils/transformations/schedule_interf.ml
index 48f3479..8876025 100644
--- a/compiler/minils/transformations/schedule_interf.ml
+++ b/compiler/minils/transformations/schedule_interf.ml
@@ -51,7 +51,14 @@ let compute_uses eqs =
       else
         Env.add x 1 env
     in
-    List.fold_left incr_uses env (Mls_utils.Vars.read false eq)
+    let reads = Mls_utils.Vars.read false eq in
+    (* self uses not counted *)
+    let defs = Mls_utils.Vars.def [] eq in
+    let reads =
+      List.fold_left
+	(fun acc x -> if List.mem x defs then acc else (x::acc))
+	[] reads in
+    List.fold_left incr_uses env reads
   in
   List.fold_left aux Env.empty eqs
 
@@ -73,7 +80,8 @@ let decr_uses env x =
     Env.add x ((Env.find x env) - 1) env
   with
     | Not_found ->
-        Interference.print_debug "Cannot decrease; var not found : %a@." print_ident x; assert false
+	(* Self use: no decrease for x *)
+	env
 
 module Cost =
 struct
@@ -92,7 +100,8 @@ struct
         if Env.find x env = 1 then acc + 1 else acc
       with
         | Not_found ->
-          Format.printf "Var not found in kill_vars: %a@." print_ident x; assert false
+	    (* self use of x *)
+	    acc
     in
     List.fold_left is_killed 0 (Mls_utils.Vars.read false eq)
 
@@ -172,6 +181,7 @@ let remove_eq eq node_list =
 
 (** Main function to schedule a node. *)
 let schedule eq_list inputs node_list =
+  (* Compute number of uses of each ident *)
   let uses = compute_uses eq_list in
   let rec schedule_aux rem_eqs sched_eqs node_list ck costs =
     match rem_eqs with
@@ -203,8 +213,11 @@ let schedule_contract contract c_inputs =
       c.c_controllables
 
 let node _ () f =
+  (* Put memory variables into Interference.World.memories *)
   Interference.World.init f;
+  (* Schedule contract *)
   let contract,controllables = schedule_contract f.n_contract (f.n_input@f.n_output) in
+  (* Build dataflow dependency graph *)
   let node_list, _ = DataFlowDep.build f.n_equs in
   (* Controllable variables are considered as inputs *)
   let f = { f with