fix overflow

spaceandtimelabs · Nov 5, 2024 · 0692361 · 0692361
1 parent 559c83e
commit 0692361
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Showing 3 changed files with 15 additions and 2 deletions.
diff --git a/sxt/multiexp/pippenger2/variable_length_computation.cc b/sxt/multiexp/pippenger2/variable_length_computation.cc
@@ -17,6 +17,7 @@
 #include "sxt/multiexp/pippenger2/variable_length_computation.h"
 
 #include <algorithm>
+#include <numeric>
 
 #include "sxt/base/error/assert.h"
 
@@ -59,4 +60,11 @@ void compute_product_length_table(basct::span<unsigned>& product_lengths,
   }
   product_lengths = product_lengths.subspan(0, product_index);
 }
+
+//--------------------------------------------------------------------------------------------------
+// count_products
+//--------------------------------------------------------------------------------------------------
+size_t count_products(basct::cspan<unsigned> output_bit_table) noexcept {
+  return std::accumulate(output_bit_table.begin(), output_bit_table.end(), 0ull);
+}
 } // namespace sxt::mtxpp2
diff --git a/sxt/multiexp/pippenger2/variable_length_computation.h b/sxt/multiexp/pippenger2/variable_length_computation.h
@@ -26,4 +26,9 @@ void compute_product_length_table(basct::span<unsigned>& product_lengths,
                                   basct::cspan<unsigned> bit_widths,
                                   basct::cspan<unsigned> output_lengths, unsigned first,
                                   unsigned length) noexcept;
+
+//--------------------------------------------------------------------------------------------------
+// count_products
+//--------------------------------------------------------------------------------------------------
+size_t count_products(basct::cspan<unsigned> output_bit_table) noexcept;
 } // namespace sxt::mtxpp2
diff --git a/sxt/multiexp/pippenger2/variable_length_multiexponentiation.h b/sxt/multiexp/pippenger2/variable_length_multiexponentiation.h
@@ -158,7 +158,7 @@ multiexponentiate_impl(basct::span<T> res, const partition_table_accessor<U>& ac
                        basct::cspan<unsigned> output_lengths, basct::cspan<uint8_t> scalars,
                        const multiexponentiate_options& options) noexcept {
   auto num_outputs = res.size();
-  auto num_products = std::accumulate(output_bit_table.begin(), output_bit_table.end(), 0u);
+  auto num_products = count_products(output_bit_table);
   auto num_output_bytes = basn::divide_up<size_t>(num_products, 8);
   if (num_outputs == 0) {
     co_return;
@@ -224,7 +224,7 @@ void multiexponentiate(basct::span<T> res, const partition_table_accessor<U>& ac
                        basct::cspan<unsigned> output_lengths,
                        basct::cspan<uint8_t> scalars) noexcept {
   auto num_outputs = res.size();
-  auto num_products = std::accumulate(output_bit_table.begin(), output_bit_table.end(), 0u);
+  auto num_products = count_products(output_bit_table);
   auto num_output_bytes = basn::divide_up<size_t>(num_products, 8);
   if (num_outputs == 0) {
     return;