No-ops on best_multiexp and best_fft when #[cfg(feature=counter)]

Co-authored-by: Andrija <akinovak@gmail.com>

halo2_proofs/src/arithmetic.rs

@@ -165,6 +165,8 @@ pub fn best_multiexp<C: CurveAffine>(coeffs: &[C::Scalar], bases: &[C]) -> C::Cu
             .entry(coeffs.len())
             .and_modify(|cnt| *cnt += 1)
             .or_insert(1);
+
+        return C::Curve::generator();
     }
 
     assert_eq!(coeffs.len(), bases.len());
@@ -215,6 +217,8 @@ pub fn best_fft<Scalar: Field, G: FftGroup<Scalar>>(a: &mut [G], omega: Scalar,
             .entry(a.len())
             .and_modify(|cnt| *cnt += 1)
             .or_insert(1);
+
+        return;
     }
 
     fn bitreverse(mut n: usize, l: usize) -> usize {

halo2_proofs/src/plonk/keygen.rs

@@ -210,6 +210,7 @@ where
         _marker: std::marker::PhantomData,
     };
 
+    #[cfg(not(feature = "counter"))]
     // Synthesize the circuit to obtain URS
     ConcreteCircuit::FloorPlanner::synthesize(
         &mut assembly,
@@ -271,6 +272,7 @@ where
         _marker: std::marker::PhantomData,
     };
 
+    #[cfg(not(feature = "counter"))]
     // Synthesize the circuit to obtain URS
     ConcreteCircuit::FloorPlanner::synthesize(
         &mut assembly,

halo2_proofs/src/plonk/prover.rs

@@ -290,6 +290,7 @@ pub fn create_proof<
                 _marker: std::marker::PhantomData,
             };
 
+            #[cfg(not(feature = "counter"))]
             // Synthesize the circuit to obtain the witness and other information.
             ConcreteCircuit::FloorPlanner::synthesize(
                 &mut witness,
@@ -741,6 +742,8 @@ pub fn create_proof<
         // reset counters at the end of the proving
         *MSM_COUNTER.lock().unwrap() = BTreeMap::new();
         *FFT_COUNTER.lock().unwrap() = BTreeMap::new();
+
+        return Ok(());
     }
 
     multiopen::create_proof(params, rng, transcript, instances).map_err(|_| Error::Opening)