From 297224a809d7d368ddb45cb8a9e15c516f4405cc Mon Sep 17 00:00:00 2001
From: cgouert <cgouert@udel.edu>
Date: Mon, 19 Jun 2023 17:56:43 -0400
Subject: [PATCH] Update sorting algorithm for sequential circuits

---
 hdl-benchmarks |  2 +-
 src/circuit.rs | 27 +++++++++++++++++----------
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/hdl-benchmarks b/hdl-benchmarks
index 3b2cdab..50b0bfe 160000
--- a/hdl-benchmarks
+++ b/hdl-benchmarks
@@ -1 +1 @@
-Subproject commit 3b2cdab6ffdd335e86c2658f08bd8d95aa4ef2da
+Subproject commit 50b0bfe6ac9377ea385726009035628c10fd39ab
diff --git a/src/circuit.rs b/src/circuit.rs
index 3651654..fdb231a 100644
--- a/src/circuit.rs
+++ b/src/circuit.rs
@@ -105,22 +105,29 @@ impl<'a> Circuit<'a> {
             wire_status.insert(input.clone());
         });
 
+        let mut dff_level = Vec::new();
         while !self.gates.is_empty() {
             // Temporary vector to store retained gates
             let mut level = Vec::new();
             let mut next_wire_status = HashSet::new();
-
+            let mut ready = false;
             self.gates.retain(|gate| {
-                let ready = gate
-                    .get_input_wires()
-                    .iter()
-                    .all(|wire| wire_status.contains(wire));
-
-                if ready {
+                if gate.get_gate_type() == GateType::Dff {
                     next_wire_status.insert(gate.get_output_wire());
-                    level.push(gate.clone());
+                    dff_level.push(gate.clone());
+                    ready = true;
+                }
+                else {
+                    ready = gate
+                        .get_input_wires()
+                        .iter()
+                        .all(|wire| wire_status.contains(wire));
+
+                    if ready {
+                        next_wire_status.insert(gate.get_output_wire());
+                        level.push(gate.clone());
+                    }
                 }
-
                 !ready
             });
 
@@ -130,7 +137,7 @@ impl<'a> Circuit<'a> {
             level.sort();
             self.ordered_gates.extend(level);
         }
-
+        self.ordered_gates.extend(dff_level);
         // Remove all the gates after sorting is done. Use ordered_gates from
         // now on.
         self.gates.clear();