populate ultra ops only through function

barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/goblin_ultra_circuit_builder.cpp

@@ -170,15 +170,7 @@ ecc_op_tuple GoblinUltraCircuitBuilder_<FF>::decompose_ecc_operands(uint32_t op_
     z_2 = z_2.to_montgomery_form();
 
     // Populate ultra ops in OpQueue with the decomposed operands
-    op_queue->ultra_ops[0].emplace_back(this->variables[op_idx]);
-    op_queue->ultra_ops[1].emplace_back(x_lo);
-    op_queue->ultra_ops[2].emplace_back(x_hi);
-    op_queue->ultra_ops[3].emplace_back(y_lo);
-
-    op_queue->ultra_ops[0].emplace_back(this->zero_idx);
-    op_queue->ultra_ops[1].emplace_back(y_hi);
-    op_queue->ultra_ops[2].emplace_back(z_1);
-    op_queue->ultra_ops[3].emplace_back(z_2);
+    op_queue->populate_ultra_ops({ this->variables[op_idx], x_lo, x_hi, y_lo, y_hi, z_1, z_2 });
 
     // Add variables for decomposition and get indices needed for op wires
     auto x_lo_idx = this->add_variable(x_lo);

barretenberg/cpp/src/barretenberg/proof_system/op_queue/ecc_op_queue.hpp

@@ -7,6 +7,17 @@ namespace bb {
 
 enum EccOpCode { NULL_OP, ADD_ACCUM, MUL_ACCUM, EQUALITY };
 
+struct UltraOpTuple {
+    using Fr = curve::BN254::ScalarField;
+    Fr op;
+    Fr x_lo;
+    Fr x_hi;
+    Fr y_lo;
+    Fr y_hi;
+    Fr z_1;
+    Fr z_2;
+};
+
 /**
  * @brief Used to construct execution trace representations of elliptic curve operations.
  *
@@ -34,7 +45,6 @@ class ECCOpQueue {
     size_t previous_ultra_ops_size = 0; // M_{i-1}
 
     std::array<Point, 4> ultra_ops_commitments;
-    std::array<Point, 4> previous_ultra_ops_commitments;
 
     Point get_accumulator() { return accumulator; }
 
@@ -75,7 +85,6 @@ class ECCOpQueue {
         previous_ultra_ops_size += previous.ultra_ops[0].size();
         // Update commitments
         ultra_ops_commitments = previous.ultra_ops_commitments;
-        previous_ultra_ops_commitments = previous.previous_ultra_ops_commitments;
     }
     /**
      * @brief Prepend the information from the previous queue (used before accumulation/merge proof to be able to run
@@ -104,10 +113,7 @@ class ECCOpQueue {
         lhs.previous_ultra_ops_size = rhs.previous_ultra_ops_size;
         rhs.previous_ultra_ops_size = temp;
         // Swap commitments
-        auto commit_temp = lhs.previous_ultra_ops_commitments;
-        lhs.previous_ultra_ops_commitments = rhs.previous_ultra_ops_commitments;
-        rhs.previous_ultra_ops_commitments = commit_temp;
-        commit_temp = lhs.ultra_ops_commitments;
+        auto commit_temp = lhs.ultra_ops_commitments;
         lhs.ultra_ops_commitments = rhs.ultra_ops_commitments;
         rhs.ultra_ops_commitments = commit_temp;
     }
@@ -127,11 +133,7 @@ class ECCOpQueue {
     [[nodiscard]] size_t get_previous_size() const { return previous_ultra_ops_size; }
     [[nodiscard]] size_t get_current_size() const { return current_ultra_ops_size; }
 
-    void set_commitment_data(std::array<Point, 4>& commitments)
-    {
-        previous_ultra_ops_commitments = ultra_ops_commitments;
-        ultra_ops_commitments = commitments;
-    }
+    void set_commitment_data(std::array<Point, 4>& commitments) { ultra_ops_commitments = commitments; }
 
     /**
      * @brief Get a 'view' of the current ultra ops object
@@ -281,6 +283,19 @@ class ECCOpQueue {
             .mul_scalar_full = 0,
         });
     }
+
+    void populate_ultra_ops(UltraOpTuple tuple)
+    {
+        ultra_ops[0].emplace_back(tuple.op);
+        ultra_ops[1].emplace_back(tuple.x_lo);
+        ultra_ops[2].emplace_back(tuple.x_hi);
+        ultra_ops[3].emplace_back(tuple.y_lo);
+
+        ultra_ops[0].emplace_back(0);
+        ultra_ops[1].emplace_back(tuple.y_hi);
+        ultra_ops[2].emplace_back(tuple.z_1);
+        ultra_ops[3].emplace_back(tuple.z_2);
+    }
 };
 
 } // namespace bb

barretenberg/cpp/src/barretenberg/ultra_honk/goblin_ultra_composer.test.cpp

@@ -199,10 +199,11 @@ TEST_F(GoblinUltraHonkComposerTests, MultipleCircuitsHonkAndMerge)
     // Compute the commitments to the aggregate op queue directly and check that they match those that were computed
     // iteratively during transcript aggregation by the provers and stored in the op queue.
     size_t aggregate_op_queue_size = op_queue->current_ultra_ops_size;
+    auto ultra_ops = op_queue->get_aggregate_transcript();
     auto commitment_key = std::make_shared<CommitmentKey>(aggregate_op_queue_size);
     size_t idx = 0;
     for (auto& result : op_queue->ultra_ops_commitments) {
-        auto expected = commitment_key->commit(op_queue->ultra_ops[idx++]);
+        auto expected = commitment_key->commit(ultra_ops[idx++]);
         EXPECT_EQ(result, expected);
     }
 }

barretenberg/cpp/src/barretenberg/ultra_honk/merge_prover.cpp

@@ -11,10 +11,10 @@ namespace bb {
 template <class Flavor>
 MergeProver_<Flavor>::MergeProver_(const std::shared_ptr<ECCOpQueue>& op_queue)
     : op_queue(op_queue)
-    , pcs_commitment_key(std::make_shared<CommitmentKey>(op_queue->ultra_ops[0].size()))
 {
     // Update internal size data in the op queue that allows for extraction of e.g. previous aggregate transcript
     op_queue->set_size_data();
+    pcs_commitment_key = std::make_shared<CommitmentKey>(op_queue->current_ultra_ops_size);
 }
 
 /**