More generic, less efficient

AztecProtocol · Apr 18, 2024 · ce98798 · ce98798
1 parent d24fec3
commit ce98798
Show file tree

Hide file tree

Showing 2 changed files with 17 additions and 17 deletions.
diff --git a/barretenberg/cpp/src/barretenberg/polynomials/univariate.hpp b/barretenberg/cpp/src/barretenberg/polynomials/univariate.hpp
@@ -271,9 +271,10 @@ template <class Fr, size_t domain_end, size_t domain_start = 0> class Univariate
      * subtraction: setting Δ = v1-v0, the values of f(X) are f(0)=v0, f(1)= v0 + Δ, v2 = f(1) + Δ, v3 = f(2) + Δ...
      *
      */
-    template <size_t EXTENDED_DOMAIN_END, bool optimised = false> Univariate<Fr, EXTENDED_DOMAIN_END> extend_to() const
+    template <size_t EXTENDED_DOMAIN_END, size_t NUM_SKIPPED_INDICES = 0>
+    Univariate<Fr, EXTENDED_DOMAIN_END> extend_to() const
     {
-        const size_t EXTENDED_LENGTH = EXTENDED_DOMAIN_END - domain_start;
+        const size_t EXTENDED_LENGTH = EXTENDED_DOMAIN_END - domain_start + NUM_SKIPPED_INDICES;
         using Data = BarycentricData<Fr, LENGTH, EXTENDED_LENGTH>;
         static_assert(EXTENDED_LENGTH >= LENGTH);
 
@@ -282,22 +283,13 @@ template <class Fr, size_t domain_end, size_t domain_start = 0> class Univariate
         std::copy(evaluations.begin(), evaluations.end(), result.evaluations.begin());
 
         static constexpr Fr inverse_two = Fr(2).invert();
-        // static_assert(!optimised || (LENGTH <= 2));
+        static_assert(NUM_SKIPPED_INDICES < LENGTH);
         if constexpr (LENGTH == 2) {
             Fr delta = value_at(1) - value_at(0);
             static_assert(EXTENDED_LENGTH != 0);
-            if constexpr (optimised) {
-                Fr current = result.value_at(1);
-                for (size_t idx = domain_end - 2; idx < EXTENDED_DOMAIN_END - 1; idx++) {
-                    current += delta;
-                    result.value_at(idx + 1) = current;
-                }
-            } else {
-                for (size_t idx = domain_end - 1; idx < EXTENDED_DOMAIN_END - 1; idx++) {
-                    result.value_at(idx + 1) = result.value_at(idx) + delta;
-                }
+            for (size_t idx = domain_end - 1; idx < EXTENDED_DOMAIN_END - 1; idx++) {
+                result.value_at(idx + 1) = result.value_at(idx) + delta;
             }
-            return result;
         } else if constexpr (LENGTH == 3) {
             // Based off https://hackmd.io/@aztec-network/SyR45cmOq?type=view
             // The technique used here is the same as the length == 3 case below.
@@ -313,7 +305,6 @@ template <class Fr, size_t domain_end, size_t domain_start = 0> class Univariate
                 result.value_at(idx + 1) = result.value_at(idx) + extra;
                 extra += a2;
             }
-            return result;
         } else if constexpr (LENGTH == 4) {
             static constexpr Fr inverse_six = Fr(6).invert(); // computed at compile time for efficiency
 
@@ -377,7 +368,6 @@ template <class Fr, size_t domain_end, size_t domain_start = 0> class Univariate
 
                 linear_term += three_a_plus_two_b;
             }
-            return result;
         } else {
             for (size_t k = domain_end; k != EXTENDED_DOMAIN_END; ++k) {
                 result.value_at(k) = 0;
@@ -390,8 +380,17 @@ template <class Fr, size_t domain_end, size_t domain_start = 0> class Univariate
                 // scale the sum by the the value of of B(x)
                 result.value_at(k) *= Data::full_numerator_values[k];
             }
+        }
+        if constexpr (NUM_SKIPPED_INDICES == 0) {
             return result;
         }
+        Univariate<Fr, EXTENDED_LENGTH - NUM_SKIPPED_INDICES> optimised_result;
+        optimised_result.value_at(0) = result.value_at(0);
+
+        std::copy(std::next(result.begin(), 1 + NUM_SKIPPED_INDICES),
+                  result.evaluations.end(),
+                  std::next(optimised_result.begin(), 1));
+        return optimised_result;
     }
 
     /**

diff --git a/barretenberg/cpp/src/barretenberg/protogalaxy/protogalaxy_prover.hpp b/barretenberg/cpp/src/barretenberg/protogalaxy/protogalaxy_prover.hpp
@@ -311,7 +311,8 @@ template <class ProverInstances_> class ProtoGalaxyProver_ {
     {
         auto base_univariates = instances.row_to_univariates(row_idx);
         for (auto [extended_univariate, base_univariate] : zip_view(extended_univariates.get_all(), base_univariates)) {
-            extended_univariate = base_univariate.template extend_to<OptimisedExtendedUnivariate::LENGTH, true>();
+            extended_univariate =
+                base_univariate.template extend_to<OptimisedExtendedUnivariate::LENGTH, ProverInstances::NUM - 1>();
         }
     }