Merge pull request #1396 from AntelopeIO/merkle_c++20_ifdefs_remove

remove C++20 ifdefs in merkle.hpp

Author: spoonincode

libraries/chain/include/eosio/chain/incremental_merkle.hpp

@@ -31,9 +31,9 @@ namespace eosio::chain {
 class incremental_merkle_tree {
 public:
    void append(const digest_type& digest) {
-      assert(trees.size() == static_cast<size_t>(detail::popcount(mask)));
+      assert(trees.size() == static_cast<size_t>(std::popcount(mask)));
       _append(digest, trees.end(), 0);
-      assert(trees.size() == static_cast<size_t>(detail::popcount(mask)));
+      assert(trees.size() == static_cast<size_t>(std::popcount(mask)));
    }
 
    digest_type get_root() const {

libraries/chain/include/eosio/chain/merkle.hpp

@@ -9,14 +9,6 @@ namespace eosio::chain {
 
 namespace detail {
 
-#if __cplusplus >= 202002L
-   inline int      popcount(uint64_t x)  noexcept { return std::popcount(x); }
-   inline uint64_t bit_floor(uint64_t x) noexcept { return std::bit_floor(x); }
-#else
-   inline int      popcount(uint64_t x)  noexcept { return __builtin_popcountll(x); }
-   inline uint64_t bit_floor(uint64_t x) noexcept { return x == 0 ? 0ull : 1ull << (64 - 1 - __builtin_clzll(x)); }
-#endif
-
 inline digest_type hash_combine(const digest_type& a, const digest_type& b) {
    return digest_type::hash(std::make_pair(std::cref(a), std::cref(b)));
 }
@@ -26,7 +18,7 @@ requires std::is_same_v<std::decay_t<typename std::iterator_traits<It>::value_ty
 inline digest_type calculate_merkle_pow2(const It& start, const It& end) {
    assert(end >= start + 2);
    auto size = static_cast<size_t>(end - start);
-   assert(detail::bit_floor(size) == size);
+   assert(std::bit_floor(size) == size);
 
    if (size == 2)
       return hash_combine(start[0], start[1]);
@@ -76,17 +68,15 @@ inline digest_type calculate_merkle_pow2(const It& start, const It& end) {
 // appended (or 0.25% of default 2MB thread stack size on Ubuntu).
 // ------------------------------------------------------------------------
 template <class It>
-#if __cplusplus >= 202002L
 requires std::random_access_iterator<It> &&
          std::is_same_v<std::decay_t<typename std::iterator_traits<It>::value_type>, digest_type>
-#endif
 inline digest_type calculate_merkle(const It& start, const It& end) {
    assert(end >= start);
    auto size = static_cast<size_t>(end - start);
    if (size <= 1)
       return (size == 0) ? digest_type{} : *start;
 
-   auto midpoint = detail::bit_floor(size);
+   auto midpoint = std::bit_floor(size);
    if (size == midpoint)
       return detail::calculate_merkle_pow2<It, true>(start, end);
 
@@ -102,10 +92,8 @@ inline digest_type calculate_merkle(const It& start, const It& end) {
 // for the sequence of digests in the container.
 // --------------------------------------------------------------------------
 template <class Cont>
-#if __cplusplus >= 202002L
 requires std::random_access_iterator<decltype(Cont().begin())> &&
          std::is_same_v<std::decay_t<typename Cont::value_type>, digest_type>
-#endif
 inline digest_type calculate_merkle(const Cont& ids) {
    return calculate_merkle(ids.begin(), ids.end()); // cbegin not supported for std::span until C++23.
 }