forkify fixes

hercules_opt/src/forkify.rs

@@ -439,6 +439,10 @@ pub fn analyze_phis<'a>(
     phis: &'a [NodeID],
     loop_nodes: &'a HashSet<NodeID>,
 ) -> impl Iterator<Item = LoopPHI> + 'a {
+
+    // Find data cycles within the loop of this phi, 
+    // Start from the phis loop_continue_latch, and walk its uses until we find the original phi. 
+
     phis.into_iter().map(move |phi| {
         let stop_on: HashSet<NodeID> = editor
             .node_ids()
@@ -451,6 +455,12 @@ pub fn analyze_phis<'a>(
                         return true;
                     }
                 }
+
+                // This phi
+                if node == phi {
+                    return true;
+                }
+
                 // External Reduce
                 if let Node::Reduce {
                     control,
@@ -480,10 +490,9 @@ pub fn analyze_phis<'a>(
             .unwrap();
 
         let loop_continue_latch = editor.node(phi).try_phi().unwrap().1[continue_idx];
-
-        // TODO: We may need to stop on exiting the loop for looking for data cycles.
+        
         let uses = walk_all_uses_stop_on(loop_continue_latch, editor, stop_on.clone());
-        let users = walk_all_users_stop_on(loop_continue_latch, editor, stop_on.clone());
+        let users = walk_all_users_stop_on(*phi, editor, stop_on.clone());
 
         let other_stop_on: HashSet<NodeID> = editor
             .node_ids()
@@ -514,8 +523,7 @@ pub fn analyze_phis<'a>(
             .collect();
         
 
-
-        let mut uses_for_dependance = walk_all_users_stop_on(loop_continue_latch, editor, other_stop_on);
+        let mut uses_for_dependance = walk_all_uses_stop_on(loop_continue_latch, editor, other_stop_on);
 
         let set1: HashSet<_> = HashSet::from_iter(uses);
         let set2: HashSet<_> = HashSet::from_iter(users);
@@ -539,7 +547,6 @@ pub fn analyze_phis<'a>(
             if intersection
                 .iter()
                 .filter(|node| **node != loop_continue_latch )
-                .filter(|node| !(editor.node(*node).is_reduce() || editor.node(*node).is_phi()))
                 .any(|data_node| {
                     editor
                         .get_users(*data_node)