From ebcfde1d81892fc16aba4a6cac864c56a232b3a4 Mon Sep 17 00:00:00 2001
From: Nicholas Ward <npward@berkeley.edu>
Date: Thu, 7 Oct 2021 09:25:57 -0700
Subject: [PATCH] updates

---
 src/gadgets/arithmetic_u32.rs | 42 ++++++++++-------------------------
 src/gates/arithmetic_u32.rs   |  6 ++---
 2 files changed, 14 insertions(+), 34 deletions(-)

diff --git a/src/gadgets/arithmetic_u32.rs b/src/gadgets/arithmetic_u32.rs
index 7c5fe218..213cdffe 100644
--- a/src/gadgets/arithmetic_u32.rs
+++ b/src/gadgets/arithmetic_u32.rs
@@ -1,15 +1,10 @@
-use std::collections::BTreeMap;
 use std::marker::PhantomData;
 
 use crate::field::field_types::RichField;
-use crate::field::{extension_field::Extendable, field_types::Field};
+use crate::field::extension_field::Extendable;
 use crate::gates::arithmetic_u32::{U32ArithmeticGate, NUM_U32_ARITHMETIC_OPS};
-use crate::gates::switch::SwitchGate;
-use crate::iop::generator::{GeneratedValues, SimpleGenerator};
 use crate::iop::target::Target;
-use crate::iop::witness::{PartitionWitness, Witness};
 use crate::plonk::circuit_builder::CircuitBuilder;
-use crate::util::bimap::bimap_from_lists;
 
 pub struct U32Target(Target);
 
@@ -20,8 +15,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
 
     pub fn add_virtual_u32_targets(&self, n: usize) -> Vec<U32Target> {
         self.add_virtual_targets(n)
-            .iter()
-            .cloned()
+            .into_iter()
             .map(U32Target)
             .collect()
     }
@@ -52,9 +46,6 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             Some((gate_index, copy)) => (gate_index, copy),
         };
 
-        let output_low = self.add_virtual_u32_target();
-        let output_high = self.add_virtual_u32_target();
-
         self.connect(
             Target::wire(
                 gate_index,
@@ -73,27 +64,18 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             Target::wire(gate_index, U32ArithmeticGate::<F, D>::wire_ith_addend(copy)),
             z.0,
         );
-        self.connect(
-            Target::wire(
-                gate_index,
-                U32ArithmeticGate::<F, D>::wire_ith_output_low_half(copy),
-            ),
-            output_low.0,
-        );
-        self.connect(
-            Target::wire(
-                gate_index,
-                U32ArithmeticGate::<F, D>::wire_ith_output_high_half(copy),
-            ),
-            output_high.0,
-        );
+
+        let output_low = U32Target(Target::wire(
+            gate_index,
+            U32ArithmeticGate::<F, D>::wire_ith_output_low_half(copy),
+        ));
+        let output_high = U32Target(Target::wire(
+            gate_index,
+            U32ArithmeticGate::<F, D>::wire_ith_output_high_half(copy),
+        ));
 
         if copy == NUM_U32_ARITHMETIC_OPS - 1 {
-            let gate = U32ArithmeticGate {
-                _phantom: PhantomData,
-            };
-            let gate_index = self.add_gate(gate, vec![]);
-            self.current_u32_arithmetic_gate = Some((gate_index, 0));
+            self.current_u32_arithmetic_gate = None;
         } else {
             self.current_u32_arithmetic_gate = Some((gate_index, copy + 1));
         }
diff --git a/src/gates/arithmetic_u32.rs b/src/gates/arithmetic_u32.rs
index c05cf72f..b56af0e8 100644
--- a/src/gates/arithmetic_u32.rs
+++ b/src/gates/arithmetic_u32.rs
@@ -309,8 +309,7 @@ impl<F: RichField + Extendable<D>, const D: usize> SimpleGenerator<F>
         .take(num_limbs)
         .collect();
         let output_limbs_f: Vec<_> = output_limbs_u64
-            .iter()
-            .cloned()
+            .into_iter()
             .map(F::from_canonical_u64)
             .collect();
 
@@ -385,8 +384,7 @@ mod tests {
                     output /= limb_base;
                 }
                 let mut output_limbs_f: Vec<_> = output_limbs
-                    .iter()
-                    .cloned()
+                    .into_iter()
                     .map(F::from_canonical_u64)
                     .collect();