diff --git a/src/bin/bench_field_mul.rs b/src/bin/bench_field_mul.rs
index 66b36ffd..2953e4bd 100644
--- a/src/bin/bench_field_mul.rs
+++ b/src/bin/bench_field_mul.rs
@@ -1,3 +1,5 @@
+//! Performs a single exponentiation.
+
 use std::time::Instant;
 
 use plonky2::field::crandall_field::CrandallField;
@@ -5,20 +7,19 @@ use plonky2::field::field::Field;
 
 type F = CrandallField;
 
+const EXPONENT: usize = 1000000000;
+
 fn main() {
-    let m = F::from_canonical_u64(12345678901234567890);
-    let mut x = F::ONE;
+    let base = F::rand();
+    let mut state = F::ONE;
+
     let start = Instant::now();
-    let num_muls = 2000000000;
-    for _ in 0..num_muls {
-        x *= m;
+    for _ in 0..EXPONENT {
+        state *= base;
     }
     let duration = start.elapsed();
 
-    println!("result {:?}", x);
-    println!("took {:?}", duration);
-    println!(
-        "avg {:?}ns",
-        duration.as_secs_f64() * 1e9 / (num_muls as f64)
-    );
+    println!("Result: {:?}", state);
+    println!("Average field mul: {:?}ns",
+             duration.as_secs_f64() * 1e9 / EXPONENT as f64);
 }
diff --git a/src/bin/bench_field_mul_interleaved.rs b/src/bin/bench_field_mul_interleaved.rs
new file mode 100644
index 00000000..b79a93a4
--- /dev/null
+++ b/src/bin/bench_field_mul_interleaved.rs
@@ -0,0 +1,33 @@
+//! Performs several exponentiations in an interleaved loop, to enable parallelism on the core.
+
+use std::time::Instant;
+
+use plonky2::field::crandall_field::CrandallField;
+use plonky2::field::field::Field;
+
+type F = CrandallField;
+
+/// The number of exponentiations to perform in parallel.
+const WIDTH: usize = 6;
+
+const EXPONENT: usize = 1000000000;
+
+fn main() {
+    let mut bases = [F::ZERO; WIDTH];
+    for i in 0..WIDTH {
+        bases[i] = F::rand();
+    }
+    let mut state = [F::ONE; WIDTH];
+
+    let start = Instant::now();
+    for _ in 0..EXPONENT {
+        for i in 0..WIDTH {
+            state[i] *= bases[i];
+        }
+    }
+    let duration = start.elapsed();
+
+    println!("Result: {:?}", state);
+    println!("Average field mul: {:?}ns",
+             duration.as_secs_f64() * 1e9 / (WIDTH * EXPONENT) as f64);
+}
diff --git a/src/gadgets/split_join.rs b/src/gadgets/split_join.rs
index e4dd2c78..eb532ff7 100644
--- a/src/gadgets/split_join.rs
+++ b/src/gadgets/split_join.rs
@@ -14,12 +14,13 @@ impl<F: Field> CircuitBuilder<F> {
     /// enforced elsewhere.
     pub(crate) fn split_le_virtual(&mut self, integer: Target, num_bits: usize) -> Vec<Target> {
         let bit_targets = self.add_virtual_advice_targets(num_bits);
-        split_le_generator::<F>(integer, bit_targets.clone());
+        self.add_generator(SplitGenerator { integer, bits: bit_targets.clone() });
         bit_targets
     }
 }
 
 /// Generator for a little-endian split.
+#[must_use]
 pub fn split_le_generator<F: Field>(
     integer: Target,
     bits: Vec<Target>,
@@ -28,6 +29,7 @@ pub fn split_le_generator<F: Field>(
 }
 
 /// Generator for a little-endian split.
+#[must_use]
 pub fn split_le_generator_local_wires<F: Field>(
     gate: usize,
     integer_input_index: usize,
diff --git a/src/gates/gmimc.rs b/src/gates/gmimc.rs
index 26a9efa5..706b4bd1 100644
--- a/src/gates/gmimc.rs
+++ b/src/gates/gmimc.rs
@@ -62,8 +62,7 @@ impl<F: Field, const R: usize> GMiMCGate<F, R> {
 
 impl<F: Field, const R: usize> Gate<F> for GMiMCGate<F, R> {
     fn id(&self) -> String {
-        // TODO: This won't include generic params?
-        format!("{:?}", self)
+        format!("<R={}> {:?}", R, self)
     }
 
     fn eval_unfiltered(&self, vars: EvaluationVars<F>) -> Vec<F> {
@@ -273,7 +272,7 @@ mod tests {
         let gate = Gate::with_constants(constants.clone());
 
         let config = CircuitConfig {
-            num_wires: 200,
+            num_wires: 134,
             num_routed_wires: 200,
             ..Default::default()
         };
diff --git a/src/hash.rs b/src/hash.rs
index 97bb4821..d87d3e28 100644
--- a/src/hash.rs
+++ b/src/hash.rs
@@ -1,7 +1,5 @@
 //! Concrete instantiation of a hash function.
 
-use std::convert::TryInto;
-
 use rayon::prelude::*;
 
 use crate::circuit_builder::CircuitBuilder;