From dd945ef5b73bac72929677f598ac98cfc806f166 Mon Sep 17 00:00:00 2001
From: Nicholas Ward <npward@berkeley.edu>
Date: Wed, 10 Nov 2021 11:19:06 -0800
Subject: [PATCH] addressed comments

---
 src/gadgets/biguint.rs   | 13 ++++++-------
 src/gadgets/nonnative.rs | 14 ++++----------
 2 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/src/gadgets/biguint.rs b/src/gadgets/biguint.rs
index f9878c50..fff97a6e 100644
--- a/src/gadgets/biguint.rs
+++ b/src/gadgets/biguint.rs
@@ -61,7 +61,6 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             (a.clone(), padded_b)
         } else {
             let mut padded_a = a.clone();
-            let to_extend = b.num_limbs() - a.num_limbs();
             for _ in a.num_limbs()..b.num_limbs() {
                 padded_a.limbs.push(self.zero_u32());
             }
@@ -266,10 +265,10 @@ mod tests {
     fn test_biguint_sub() -> Result<()> {
         let mut rng = rand::thread_rng();
 
-        let x_value = BigUint::from_u128(rng.gen()).unwrap();
+        let mut x_value = BigUint::from_u128(rng.gen()).unwrap();
         let mut y_value = BigUint::from_u128(rng.gen()).unwrap();
-        while y_value > x_value {
-            y_value = BigUint::from_u128(rng.gen()).unwrap();
+        if y_value > x_value {
+            (x_value, y_value) = (y_value, x_value);
         }
         let expected_z_value = &x_value - &y_value;
 
@@ -343,10 +342,10 @@ mod tests {
     fn test_biguint_div_rem() -> Result<()> {
         let mut rng = rand::thread_rng();
 
-        let x_value = BigUint::from_u128(rng.gen()).unwrap();
+        let mut x_value = BigUint::from_u128(rng.gen()).unwrap();
         let mut y_value = BigUint::from_u128(rng.gen()).unwrap();
-        while y_value > x_value {
-            y_value = BigUint::from_u128(rng.gen()).unwrap();
+        if y_value > x_value {
+            (x_value, y_value) = (y_value, x_value);
         }
         let (expected_div_value, expected_rem_value) = x_value.div_rem(&y_value);
 
diff --git a/src/gadgets/nonnative.rs b/src/gadgets/nonnative.rs
index fbe46fe2..fd883e5d 100644
--- a/src/gadgets/nonnative.rs
+++ b/src/gadgets/nonnative.rs
@@ -44,9 +44,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         a: &ForeignFieldTarget<FF>,
         b: &ForeignFieldTarget<FF>,
     ) -> ForeignFieldTarget<FF> {
-        let a_biguint = self.nonnative_to_biguint(a);
-        let b_biguint = self.nonnative_to_biguint(b);
-        let result = self.add_biguint(&a_biguint, &b_biguint);
+        let result = self.add_biguint(&a.value, &b.value);
 
         self.reduce(&result)
     }
@@ -58,10 +56,8 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         b: &ForeignFieldTarget<FF>,
     ) -> ForeignFieldTarget<FF> {
         let order = self.constant_biguint(&FF::order());
-        let a_biguint = self.nonnative_to_biguint(a);
-        let a_plus_order = self.add_biguint(&order, &a_biguint);
-        let b_biguint = self.nonnative_to_biguint(b);
-        let result = self.sub_biguint(&a_plus_order, &b_biguint);
+        let a_plus_order = self.add_biguint(&order, &a.value);
+        let result = self.sub_biguint(&a_plus_order, &b.value);
 
         // TODO: reduce sub result with only one conditional addition?
         self.reduce(&result)
@@ -72,9 +68,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         a: &ForeignFieldTarget<FF>,
         b: &ForeignFieldTarget<FF>,
     ) -> ForeignFieldTarget<FF> {
-        let a_biguint = self.nonnative_to_biguint(a);
-        let b_biguint = self.nonnative_to_biguint(b);
-        let result = self.mul_biguint(&a_biguint, &b_biguint);
+        let result = self.mul_biguint(&a.value, &b.value);
 
         self.reduce(&result)
     }