No longer need to store number of PP polynomials (#424)

* No longer need to store number of PP polynomials

It's unused after the refactoring we did.

* PR feedback

plonky2/src/plonk/circuit_builder.rs

@@ -629,7 +629,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         let min_quotient_degree_factor = max_filtered_constraint_degree - 1;
         let max_quotient_degree_factor = self.config.max_quotient_degree_factor.min(1 << rate_bits);
         let quotient_degree_factor = (min_quotient_degree_factor..=max_quotient_degree_factor)
-            .min_by_key(|&q| num_partial_products(self.config.num_routed_wires, q).0 + q)
+            .min_by_key(|&q| num_partial_products(self.config.num_routed_wires, q) + q)
             .unwrap();
         debug!("Quotient degree factor set to: {}.", quotient_degree_factor);
 

plonky2/src/plonk/circuit_data.rs

@@ -237,9 +237,8 @@ pub struct CommonCircuitData<
     /// The `{k_i}` valued used in `S_ID_i` in Plonk's permutation argument.
     pub(crate) k_is: Vec<F>,
 
-    /// The number of partial products needed to compute the `Z` polynomials and
-    /// the number of original elements consumed in `partial_products()`.
-    pub(crate) num_partial_products: (usize, usize),
+    /// The number of partial products needed to compute the `Z` polynomials.
+    pub(crate) num_partial_products: usize,
 
     /// A digest of the "circuit" (i.e. the instance, minus public inputs), which can be used to
     /// seed Fiat-Shamir.
@@ -356,7 +355,7 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
 
     fn fri_zs_partial_products_polys(&self) -> Vec<FriPolynomialInfo> {
         let num_zs_partial_products_polys =
-            self.config.num_challenges * (1 + self.num_partial_products.0);
+            self.config.num_challenges * (1 + self.num_partial_products);
         FriPolynomialInfo::from_range(
             PlonkOracle::ZS_PARTIAL_PRODUCTS.index,
             0..num_zs_partial_products_polys,

plonky2/src/plonk/prover.rs

@@ -269,7 +269,7 @@ fn wires_permutation_partial_products_and_zs<
     let degree = common_data.quotient_degree_factor;
     let subgroup = &prover_data.subgroup;
     let k_is = &common_data.k_is;
-    let (num_prods, _final_num_prod) = common_data.num_partial_products;
+    let num_prods = common_data.num_partial_products;
     let all_quotient_chunk_products = subgroup
         .par_iter()
         .enumerate()

plonky2/src/plonk/vanishing_poly.rs

@@ -37,7 +37,7 @@ pub(crate) fn eval_vanishing_poly<
     alphas: &[F],
 ) -> Vec<F::Extension> {
     let max_degree = common_data.quotient_degree_factor;
-    let (num_prods, _final_num_prod) = common_data.num_partial_products;
+    let num_prods = common_data.num_partial_products;
 
     let constraint_terms =
         evaluate_gate_constraints(&common_data.gates, common_data.num_gate_constraints, vars);
@@ -123,7 +123,7 @@ pub(crate) fn eval_vanishing_poly_base_batch<
     assert_eq!(s_sigmas_batch.len(), n);
 
     let max_degree = common_data.quotient_degree_factor;
-    let (num_prods, _final_num_prod) = common_data.num_partial_products;
+    let num_prods = common_data.num_partial_products;
 
     let num_gate_constraints = common_data.num_gate_constraints;
 
@@ -302,7 +302,7 @@ pub(crate) fn eval_vanishing_poly_recursively<
     alphas: &[Target],
 ) -> Vec<ExtensionTarget<D>> {
     let max_degree = common_data.quotient_degree_factor;
-    let (num_prods, _final_num_prod) = common_data.num_partial_products;
+    let num_prods = common_data.num_partial_products;
 
     let constraint_terms = with_context!(
         builder,

plonky2/src/util/partial_products.rs

@@ -35,16 +35,14 @@ pub(crate) fn partial_products_and_z_gx<F: Field>(z_x: F, quotient_chunk_product
     res
 }
 
-/// Returns a tuple `(a,b)`, where `a` is the length of the output of `partial_products()` on a
-/// vector of length `n`, and `b` is the number of original elements consumed in `partial_products()`.
-pub(crate) fn num_partial_products(n: usize, max_degree: usize) -> (usize, usize) {
+/// Returns the length of the output of `partial_products()` on a vector of length `n`.
+pub(crate) fn num_partial_products(n: usize, max_degree: usize) -> usize {
     debug_assert!(max_degree > 1);
     let chunk_size = max_degree;
     // We'll split the product into `ceil_div_usize(n, chunk_size)` chunks, but the last chunk will
     // be associated with Z(gx) itself. Thus we subtract one to get the chunks associated with
     // partial products.
-    let num_chunks = ceil_div_usize(n, chunk_size) - 1;
-    (num_chunks, num_chunks * chunk_size)
+    ceil_div_usize(n, chunk_size) - 1
 }
 
 /// Checks the relationship between each pair of partial product accumulators. In particular, this
@@ -127,7 +125,7 @@ mod tests {
         assert_eq!(pps_and_z_gx, field_vec(&[2, 24, 720]));
 
         let nums = num_partial_products(v.len(), 2);
-        assert_eq!(pps.len(), nums.0);
+        assert_eq!(pps.len(), nums);
         assert!(check_partial_products(&v, &denominators, pps, z_x, z_gx, 2)
             .iter()
             .all(|x| x.is_zero()));
@@ -138,7 +136,7 @@ mod tests {
         let pps = &pps_and_z_gx[..pps_and_z_gx.len() - 1];
         assert_eq!(pps_and_z_gx, field_vec(&[6, 720]));
         let nums = num_partial_products(v.len(), 3);
-        assert_eq!(pps.len(), nums.0);
+        assert_eq!(pps.len(), nums);
         assert!(check_partial_products(&v, &denominators, pps, z_x, z_gx, 3)
             .iter()
             .all(|x| x.is_zero()));

plonky2/src/util/serialization.rs

@@ -172,9 +172,8 @@ impl Buffer {
         let wires = self.read_field_ext_vec::<F, D>(config.num_wires)?;
         let plonk_zs = self.read_field_ext_vec::<F, D>(config.num_challenges)?;
         let plonk_zs_right = self.read_field_ext_vec::<F, D>(config.num_challenges)?;
-        let partial_products = self.read_field_ext_vec::<F, D>(
-            common_data.num_partial_products.0 * config.num_challenges,
-        )?;
+        let partial_products = self
+            .read_field_ext_vec::<F, D>(common_data.num_partial_products * config.num_challenges)?;
         let quotient_polys = self.read_field_ext_vec::<F, D>(
             common_data.quotient_degree_factor * config.num_challenges,
         )?;
@@ -248,7 +247,7 @@ impl Buffer {
         evals_proofs.push((wires_v, wires_p));
 
         let zs_partial_v =
-            self.read_field_vec(config.num_challenges * (1 + common_data.num_partial_products.0))?;
+            self.read_field_vec(config.num_challenges * (1 + common_data.num_partial_products))?;
         let zs_partial_p = self.read_merkle_proof()?;
         evals_proofs.push((zs_partial_v, zs_partial_p));