Removed unnecessary copying of buffer.

vendor/zkllvm-metacraft-circuits/src/circuits_impl/compute_shuffled_index_impl.h

@@ -14,24 +14,20 @@ using namespace circuit_byte_utils;
 uint64_t compute_shuffled_index_impl(uint64_t index, uint64_t index_count, Bytes32 seed, int SHUFFLE_ROUND_COUNT = 90) {
     assert_true(index < index_count);
 
-    Bytes32 source_buffer {};
-
-    std::copy(seed.begin(), seed.end(), source_buffer.begin());
-
     // Swap or not (https://link.springer.com/content/pdf/10.1007%2F978-3-642-32009-5_1.pdf)
     // See the 'generalized domain' algorithm on page 3
     for (Byte current_round = 0; current_round < SHUFFLE_ROUND_COUNT; current_round++) {
 
-        Bytes32 source_round_hash = calc_hash(source_buffer, current_round);
+        Bytes32 source_round_hash = calc_hash(seed, current_round);
         auto first8bytes = take_n_elements<8>(source_round_hash);
 
         auto first8bytes_int = bytes_to_int<uint64_t>(first8bytes);
         auto pivot = first8bytes_int % index_count;
         uint64_t flip = (pivot + index_count - index) % index_count;
         auto position = std::max(index, flip);
 
-        Bytes32 source_buffer_hash = calc_hash(source_buffer, current_round, int_to_bytes(uint32_t(position >> 8)));
-        auto byte_value = source_buffer_hash[(position % 256) >> 3];
+        Bytes32 seed_hash = calc_hash(seed, current_round, int_to_bytes(uint32_t(position >> 8)));
+        auto byte_value = seed_hash[(position % 256) >> 3];
         auto bit = (byte_value >> (position % 8)) % 2;
 
         if (bit != 0) {