From e418997d6fa0b46d2246a776712b341405c13e56 Mon Sep 17 00:00:00 2001
From: wborgeaud <williamborgeaud@gmail.com>
Date: Fri, 17 Sep 2021 13:29:59 +0200
Subject: [PATCH] Cleanup

---
 src/hash/poseidon.rs  | 26 --------------------------
 src/iop/challenger.rs |  2 +-
 2 files changed, 1 insertion(+), 27 deletions(-)

diff --git a/src/hash/poseidon.rs b/src/hash/poseidon.rs
index 16f9117d..c3a01636 100644
--- a/src/hash/poseidon.rs
+++ b/src/hash/poseidon.rs
@@ -175,15 +175,8 @@ where
         v: &[F; WIDTH],
     ) -> F {
         debug_assert!(r < WIDTH);
-        // The values of MDS_MATRIX_EXPS are known to be small, so we can
-        // accumulate all the products for each row and reduce just once
-        // at the end (done by the caller).
-
-        // NB: Unrolling this, calculating each term independently, and
-        // summing at the end, didn't improve performance for me.
         let mut res = F::ZERO;
 
-        // This is a hacky way of fully unrolling the loop.
         assert!(WIDTH <= 12);
         for i in 0..12 {
             if i < WIDTH {
@@ -203,15 +196,8 @@ where
     ) -> ExtensionTarget<D> {
         let one = builder.one_extension();
         debug_assert!(r < WIDTH);
-        // The values of MDS_MATRIX_EXPS are known to be small, so we can
-        // accumulate all the products for each row and reduce just once
-        // at the end (done by the caller).
-
-        // NB: Unrolling this, calculating each term independently, and
-        // summing at the end, didn't improve performance for me.
         let mut res = builder.zero_extension();
 
-        // This is a hacky way of fully unrolling the loop.
         assert!(WIDTH <= 12);
         for i in 0..12 {
             if i < WIDTH {
@@ -256,7 +242,6 @@ where
     ) -> [F; WIDTH] {
         let mut result = [F::ZERO; WIDTH];
 
-        // This is a hacky way of fully unrolling the loop.
         assert!(WIDTH <= 12);
         for r in 0..12 {
             if r < WIDTH {
@@ -275,7 +260,6 @@ where
     ) -> [ExtensionTarget<D>; WIDTH] {
         let mut result = [builder.zero_extension(); WIDTH];
 
-        // This is a hacky way of fully unrolling the loop.
         assert!(WIDTH <= 12);
         for r in 0..12 {
             if r < WIDTH {
@@ -361,9 +345,6 @@ where
         let one = builder.one_extension();
         let mut result = [builder.zero_extension(); WIDTH];
 
-        // Initial matrix has first row/column = [1, 0, ..., 0];
-
-        // c = 0
         result[0] = state[0];
 
         assert!(WIDTH <= 12);
@@ -372,9 +353,6 @@ where
                 assert!(WIDTH <= 12);
                 for r in 1..12 {
                     if r < WIDTH {
-                        // NB: FAST_PARTIAL_ROUND_INITIAL_MATRIX is stored in
-                        // column-major order so that this dot product is cache
-                        // friendly.
                         let t = F::from_canonical_u64(
                             Self::FAST_PARTIAL_ROUND_INITIAL_MATRIX[c - 1][r - 1],
                         );
@@ -429,8 +407,6 @@ where
         state: &[F; WIDTH],
         r: usize,
     ) -> [F; WIDTH] {
-        // Set d = [M_00 | w^] dot [state]
-
         let s0 = state[0];
         let mut d = s0 * F::from_canonical_u64(1 << Self::MDS_MATRIX_EXPS[0]);
         assert!(WIDTH <= 12);
@@ -464,7 +440,6 @@ where
         let zero = builder.zero_extension();
         let one = builder.one_extension();
 
-        // Set d = [M_00 | w^] dot [state]
         let s0 = state[0];
         let mut d = builder.arithmetic_extension(
             F::from_canonical_u64(1 << Self::MDS_MATRIX_EXPS[0]),
@@ -481,7 +456,6 @@ where
             }
         }
 
-        // result = [d] concat [state[0] * v + state[shift up by 1]]
         let mut result = [zero; WIDTH];
         result[0] = d;
         assert!(WIDTH <= 12);
diff --git a/src/iop/challenger.rs b/src/iop/challenger.rs
index 2fb43979..d33c19ce 100644
--- a/src/iop/challenger.rs
+++ b/src/iop/challenger.rs
@@ -377,7 +377,7 @@ mod tests {
         }
 
         let config = CircuitConfig::large_config();
-        let mut builder = CircuitBuilder::<F, 4>::new(config.clone());
+        let mut builder = CircuitBuilder::<F, 4>::new(config);
         let mut recursive_challenger = RecursiveChallenger::new(&mut builder);
         let mut recursive_outputs_per_round: Vec<Vec<Target>> = Vec::new();
         for (r, inputs) in inputs_per_round.iter().enumerate() {