better phi reduce condition

hercules_opt/src/forkify.rs

@@ -477,10 +477,17 @@ pub fn analyze_phis<'a>(
                 return false;
             })
             .collect();
+        
+        let continue_idx = editor
+            .get_uses(natural_loop.header)
+            .position(|node| natural_loop.control[node.idx()])
+            .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(*phi, editor, stop_on.clone());
-        let users = walk_all_users_stop_on(*phi, editor, stop_on.clone());
+        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 other_stop_on: HashSet<NodeID> = editor
             .node_ids()
@@ -509,8 +516,10 @@ pub fn analyze_phis<'a>(
                 return false;
             })
             .collect();
+        
+
 
-        let mut uses_for_dependance = walk_all_users_stop_on(*phi, editor, other_stop_on);
+        let mut uses_for_dependance = walk_all_users_stop_on(loop_continue_latch, editor, other_stop_on);
 
         let set1: HashSet<_> = HashSet::from_iter(uses);
         let set2: HashSet<_> = HashSet::from_iter(users);
@@ -523,12 +532,7 @@ pub fn analyze_phis<'a>(
             LoopPHI::LoopDependant(*phi)
         }
         else if intersection.clone().iter().any(|node| true) {
-            let continue_idx = editor
-                .get_uses(natural_loop.header)
-                .position(|node| natural_loop.control[node.idx()])
-                .unwrap();
 
-            let loop_continue_latch = editor.node(phi).try_phi().unwrap().1[continue_idx];
 
             // PHIs on the frontier of the uses by the candidate phi, i.e in uses_for_dependance need
             // to have headers that postdominate the loop continue latch. The value of the PHI used needs to be defined
@@ -538,7 +542,8 @@ pub fn analyze_phis<'a>(
             // If some other node in the cycle is used, there is not a valid node to assign it after making the cycle a reduce. 
             if intersection
                 .iter()
-                .filter(|node| **node != loop_continue_latch)
+                .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)