diff --git a/lang/src/son.rs b/lang/src/son.rs
index f6ac48c..e34b951 100644
--- a/lang/src/son.rs
+++ b/lang/src/son.rs
@@ -3800,7 +3800,7 @@ impl<'a> Function<'a> {
                     block.push(self.rg(ph));
                 }
                 self.blocks[self.nodes[nid].ralloc_backref as usize].params = block;
-                self.reschedule_block(&mut node.outputs);
+                self.reschedule_block(nid, &mut node.outputs);
                 for o in node.outputs.into_iter().rev() {
                     self.emit_node(o, nid);
                 }
@@ -3874,7 +3874,7 @@ impl<'a> Function<'a> {
                     )]);
                 }
 
-                self.reschedule_block(&mut node.outputs);
+                self.reschedule_block(nid, &mut node.outputs);
                 for o in node.outputs.into_iter().rev() {
                     self.emit_node(o, nid);
                 }
@@ -3882,7 +3882,7 @@ impl<'a> Function<'a> {
             Kind::Then | Kind::Else => {
                 self.nodes[nid].ralloc_backref = self.add_block(nid);
                 self.bridge(prev, nid);
-                self.reschedule_block(&mut node.outputs);
+                self.reschedule_block(nid, &mut node.outputs);
                 for o in node.outputs.into_iter().rev() {
                     self.emit_node(o, nid);
                 }
@@ -3983,7 +3983,7 @@ impl<'a> Function<'a> {
 
                 self.add_instr(nid, ops);
 
-                self.reschedule_block(&mut node.outputs);
+                self.reschedule_block(nid, &mut node.outputs);
                 for o in node.outputs.into_iter().rev() {
                     if self.nodes[o].inputs[0] == nid
                         || (matches!(self.nodes[o].kind, Kind::Loop | Kind::Region)
@@ -4073,7 +4073,8 @@ impl<'a> Function<'a> {
             .push(regalloc2::Block::new(self.nodes[pred].ralloc_backref as usize));
     }
 
-    fn reschedule_block(&mut self, outputs: &mut Vc) {
+    fn reschedule_block(&mut self, from: Nid, outputs: &mut Vc) {
+        let from = Some(&from);
         let mut buf = Vec::with_capacity(outputs.len());
         let mut seen = BitSet::default();
         seen.clear(self.nodes.values.len());
@@ -4089,11 +4090,11 @@ impl<'a> Function<'a> {
             buf.push(o);
             while let Some(&n) = buf.get(cursor) {
                 for &i in &self.nodes[n].inputs[1..] {
-                    if self.nodes[n].inputs.first() == self.nodes[i].inputs.first()
-                        && self.nodes[i].outputs.iter().all(|&o| {
-                            self.nodes[o].inputs.first() != self.nodes[i].inputs.first()
-                                || seen.get(o)
-                        })
+                    if from == self.nodes[i].inputs.first()
+                        && self.nodes[i]
+                            .outputs
+                            .iter()
+                            .all(|&o| self.nodes[o].inputs.first() != from || seen.get(o))
                         && seen.set(i)
                     {
                         buf.push(i);
@@ -4111,11 +4112,11 @@ impl<'a> Function<'a> {
             buf.push(o);
             while let Some(&n) = buf.get(cursor) {
                 for &i in &self.nodes[n].inputs[1..] {
-                    if self.nodes[n].inputs.first() == self.nodes[i].inputs.first()
-                        && self.nodes[i].outputs.iter().all(|&o| {
-                            self.nodes[o].inputs.first() != self.nodes[i].inputs.first()
-                                || seen.get(o)
-                        })
+                    if from == self.nodes[i].inputs.first()
+                        && self.nodes[i]
+                            .outputs
+                            .iter()
+                            .all(|&o| self.nodes[o].inputs.first() != from || seen.get(o))
                         && seen.set(i)
                     {
                         buf.push(i);
@@ -4125,7 +4126,12 @@ impl<'a> Function<'a> {
             }
         }
 
-        debug_assert!(outputs.len() == buf.len() || outputs.len() == buf.len() + 1,);
+        debug_assert!(
+            outputs.len() == buf.len() || outputs.len() == buf.len() + 1,
+            "{:?} {:?}",
+            outputs,
+            buf
+        );
 
         if buf.len() + 1 == outputs.len() {
             outputs.remove(outputs.len() - 1);