reduce ~65% proving time in HyperNova by removing the not-needed cs.f…

…inalize calls

benches/hypernova.rs

@@ -1,4 +1,5 @@
 use criterion::*;
+use pprof::criterion::{Output, PProfProfiler};
 
 use ark_bn254::{constraints::GVar as bn_GVar, Fr as bn_Fr, G1Projective as bn_G};
 use ark_grumpkin::{constraints::GVar as grumpkin_GVar, Projective as grumpkin_G};
@@ -79,5 +80,9 @@ fn bench_hypernova_ivc(c: &mut Criterion) {
     }
 }
 
-criterion_group!(benches, bench_hypernova_ivc);
+criterion_group! {
+    name = benches;
+    config = Criterion::default().with_profiler(PProfProfiler::new(100, Output::Flamegraph(None)));
+    targets = bench_hypernova_ivc
+}
 criterion_main!(benches);

benches/protogalaxy.rs

@@ -1,4 +1,5 @@
 use criterion::*;
+use pprof::criterion::{Output, PProfProfiler};
 
 use ark_bn254::{constraints::GVar as bn_GVar, Fr as bn_Fr, G1Projective as bn_G};
 use ark_grumpkin::{constraints::GVar as grumpkin_GVar, Projective as grumpkin_G};
@@ -73,5 +74,9 @@ fn bench_protogalaxy_ivc(c: &mut Criterion) {
     }
 }
 
-criterion_group!(benches, bench_protogalaxy_ivc);
+criterion_group! {
+    name = benches;
+    config = Criterion::default().with_profiler(PProfProfiler::new(100, Output::Flamegraph(None)));
+    targets = bench_protogalaxy_ivc
+}
 criterion_main!(benches);

folding-schemes/src/folding/hypernova/circuits.rs

@@ -670,7 +670,11 @@ where
         Ok(ccs)
     }
 
-    /// Returns the cs (ConstraintSystem) and the CCS out of the AugmentedFCircuit
+    /// Returns the cs (ConstraintSystem) and the CCS out of the AugmentedFCircuit.
+    /// Notice that in order to be able to internally call the `extract_r1cs` function, this method
+    /// calls the `cs.finalize` method which consumes a noticeable portion of the time. If the CCS
+    /// is not needed, directly generate the ConstraintSystem without calling the `finalize` method
+    /// will save computing time.
     #[allow(clippy::type_complexity)]
     pub fn compute_cs_ccs(
         &self,
@@ -1429,7 +1433,11 @@ mod tests {
                 cf_U_i = cf_U_i1;
             }
 
-            let (cs, _) = augmented_f_circuit.compute_cs_ccs()?;
+            let cs = ConstraintSystem::<Fr>::new_ref();
+            augmented_f_circuit
+                .clone()
+                .generate_constraints(cs.clone())?;
+            let cs = cs.into_inner().ok_or(Error::NoInnerConstraintSystem)?;
             assert!(cs.is_satisfied()?);
 
             let (r1cs_w_i1, r1cs_x_i1) = extract_w_x::<Fr>(&cs); // includes 1 and public inputs

folding-schemes/src/folding/hypernova/mod.rs

@@ -6,6 +6,7 @@ use ark_crypto_primitives::sponge::{
 use ark_ec::CurveGroup;
 use ark_ff::{BigInteger, PrimeField};
 use ark_r1cs_std::prelude::CurveVar;
+use ark_relations::r1cs::{ConstraintSynthesizer, ConstraintSystem};
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize, Compress, SerializationError};
 use ark_std::{fmt::Debug, marker::PhantomData, rand::RngCore, One, Zero};
 
@@ -427,15 +428,17 @@ where
             cf_cmT: None,
         };
 
-        let (cs, _) = augmented_f_circuit.compute_cs_ccs()?;
+        let cs = ConstraintSystem::<C1::ScalarField>::new_ref();
+        augmented_f_circuit.generate_constraints(cs.clone())?;
+        let cs = cs.into_inner().ok_or(Error::NoInnerConstraintSystem)?;
 
         #[cfg(test)]
         assert!(cs.is_satisfied()?);
 
         let (r1cs_w_i1, r1cs_x_i1) = extract_w_x::<C1::ScalarField>(&cs); // includes 1 and public inputs
 
         #[cfg(test)]
-        assert_eq!(r1cs_x_i1[0], augmented_f_circuit.x.unwrap());
+        assert_eq!(r1cs_x_i1[0], u_i1_x);
 
         let r1cs_z = [
             vec![C1::ScalarField::one()],
@@ -932,7 +935,9 @@ where
             self.cf_U_i = cf_U_i1;
         }
 
-        let (cs, _) = augmented_f_circuit.compute_cs_ccs()?;
+        let cs = ConstraintSystem::<C1::ScalarField>::new_ref();
+        augmented_f_circuit.generate_constraints(cs.clone())?;
+        let cs = cs.into_inner().ok_or(Error::NoInnerConstraintSystem)?;
 
         #[cfg(test)]
         assert!(cs.is_satisfied()?);