Rebase on master

AztecProtocol · Oct 25, 2024 · 67c4ebf · 67c4ebf
1 parent 00ed5ec
commit 67c4ebf
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Showing 4 changed files with 10 additions and 1,280 deletions.
diff --git a/barretenberg/cpp/src/barretenberg/vm/avm/generated/circuit_builder.cpp b/barretenberg/cpp/src/barretenberg/vm/avm/generated/circuit_builder.cpp
@@ -26,14 +26,15 @@ AvmCircuitBuilder::ProverPolynomials AvmCircuitBuilder::compute_polynomials() co
 
     // We create a mapping between the polynomial index and the corresponding column index when row
     // is expressed as a vector, i.e., column of the trace matrix.
+
     std::unordered_map<std::string, size_t> names_to_col_idx;
     const auto names = Row::names();
     for (size_t i = 0; i < names.size(); i++) {
         names_to_col_idx[names[i]] = i;
     }
 
     const auto labels = polys.get_unshifted_labels();
-    const size_t num_unshifted = labels.size();
+    size_t num_unshifted = labels.size();
 
     // Mapping
     std::vector<size_t> polys_to_cols_unshifted_idx(num_unshifted);
@@ -55,28 +56,11 @@ AvmCircuitBuilder::ProverPolynomials AvmCircuitBuilder::compute_polynomials() co
         "circuit_builder/init_polys_unshifted", ({
             auto unshifted = polys.get_unshifted();
 
-            // An array which stores for each column of the trace the smallest size of the
-            // truncated column containing all non-zero elements.
-            // It is used to allocate the polynomials without memory overhead for the tail of zeros.
-            std::array<size_t, Row::SIZE> col_nonzero_size{};
-
-            // Computation of size of columns.
-            // Non-parallel version takes 0.5 second for a trace size of 200k rows.
-            // A parallel version might be considered in the future.
-            for (size_t i = 0; i < num_rows; i++) {
-                const auto row = rows[i].as_vector();
-                for (size_t col = 0; col < Row::SIZE; col++) {
-                    if (!row[col].is_zero()) {
-                        col_nonzero_size[col] = i + 1;
-                    }
-                }
-            }
-
             // Set of the labels for derived/inverse polynomials.
             const auto derived_labels = polys.get_derived_labels();
             std::set<std::string> derived_labels_set(derived_labels.begin(), derived_labels.end());
 
-            bb::parallel_for(num_unshifted, [&](size_t i) {
+            bb::parallel_for(unshifted.size(), [&](size_t i) {
                 auto& poly = unshifted[i];
                 const auto col_idx = polys_to_cols_unshifted_idx[i];
                 size_t col_size = 0;
@@ -85,7 +69,13 @@ AvmCircuitBuilder::ProverPolynomials AvmCircuitBuilder::compute_polynomials() co
                 if (derived_labels_set.contains(labels[i])) {
                     col_size = num_rows;
                 } else {
-                    col_size = col_nonzero_size[col_idx];
+                    // We process each column from bottom and stops as soon as we encounter a non-zero entry.
+                    for (size_t j = 0; j < num_rows; j++) {
+                        if (!rows[num_rows - j - 1].as_vector()[col_idx].is_zero()) {
+                            col_size = num_rows - j;
+                            break;
+                        }
+                    }
                 }
 
                 if (poly.is_empty()) {