From 4ea1df82ba5d97e59556810d5ac854ac84cf2a3b Mon Sep 17 00:00:00 2001
From: Nicholas Ward <npward@berkeley.edu>
Date: Mon, 30 Aug 2021 13:14:00 -0700
Subject: [PATCH] fixes

---
 src/gadgets/permutation.rs |  3 ---
 src/gates/switch.rs        | 27 +++++++++++++++++----------
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/src/gadgets/permutation.rs b/src/gadgets/permutation.rs
index 0de5a025..06c9c711 100644
--- a/src/gadgets/permutation.rs
+++ b/src/gadgets/permutation.rs
@@ -22,7 +22,6 @@ impl<F: Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             b.len(),
             "Permutation must have same number of inputs and outputs"
         );
-        assert_eq!(a[0].len(), b[0].len(), "Chunk sizes must be the same");
 
         match a.len() {
             // Two empty lists are permutations of one another, trivially.
@@ -455,7 +454,6 @@ mod tests {
     #[test]
     fn test_permutation_2x2() -> Result<()> {
         type F = CrandallField;
-        type FF = QuarticCrandallField;
         let config = CircuitConfig::large_config();
         let pw = PartialWitness::new(config.num_wires);
         let mut builder = CircuitBuilder::<F, 4>::new(config);
@@ -482,7 +480,6 @@ mod tests {
     #[test]
     fn test_permutation_4x4() -> Result<()> {
         type F = CrandallField;
-        type FF = QuarticCrandallField;
         let config = CircuitConfig::large_config();
         let pw = PartialWitness::new(config.num_wires);
         let mut builder = CircuitBuilder::<F, 4>::new(config);
diff --git a/src/gates/switch.rs b/src/gates/switch.rs
index 50104b82..bb9553ad 100644
--- a/src/gates/switch.rs
+++ b/src/gates/switch.rs
@@ -213,10 +213,7 @@ impl<F: Extendable<D>, const D: usize, const CHUNK_SIZE: usize> SimpleGenerator<
                 SwitchGate::<F, D, CHUNK_SIZE>::wire_second_input(self.copy, e),
             ));
             deps.push(local_target(
-                SwitchGate::<F, D, CHUNK_SIZE>::wire_first_output(self.copy, e),
-            ));
-            deps.push(local_target(
-                SwitchGate::<F, D, CHUNK_SIZE>::wire_second_output(self.copy, e),
+                SwitchGate::<F, D, CHUNK_SIZE>::wire_switch_bool(self.copy, e),
             ));
         }
 
@@ -231,7 +228,11 @@ impl<F: Extendable<D>, const D: usize, const CHUNK_SIZE: usize> SimpleGenerator<
 
         let get_local_wire = |input| witness.get_wire(local_wire(input));
 
-        let switch_bool_wire = local_wire(SwitchGate::<F, D, CHUNK_SIZE>::wire_switch_bool(
+        let first_output_wire = local_wire(SwitchGate::<F, D, CHUNK_SIZE>::wire_first_output(
+            self.gate.num_copies,
+            self.copy,
+        ));
+        let second_output_wire = local_wire(SwitchGate::<F, D, CHUNK_SIZE>::wire_second_output(
             self.gate.num_copies,
             self.copy,
         ));
@@ -239,15 +240,21 @@ impl<F: Extendable<D>, const D: usize, const CHUNK_SIZE: usize> SimpleGenerator<
             let first_input = get_local_wire(SwitchGate::<F, D, CHUNK_SIZE>::wire_first_input(
                 self.copy, e,
             ));
-            let first_output = get_local_wire(SwitchGate::<F, D, CHUNK_SIZE>::wire_first_output(
+            let second_input = get_local_wire(SwitchGate::<F, D, CHUNK_SIZE>::wire_second_input(
+                self.copy, e,
+            ));
+            let switch_bool = get_local_wire(SwitchGate::<F, D, CHUNK_SIZE>::wire_switch_bool(
                 self.copy, e,
             ));
 
-            if first_input == first_output {
-                out_buffer.set_wire(switch_bool_wire, F::ONE);
+            let (first_output, second_output) = if switch_bool == F::ZERO {
+                (first_input, second_input)
             } else {
-                out_buffer.set_wire(switch_bool_wire, F::ZERO);
-            }
+                (second_input, first_input)
+            };
+
+            out_buffer.set_wire(first_output_wire, first_output);
+            out_buffer.set_wire(second_output_wire, second_output);
         }
     }
 }