+ // write_little_endian() is our utility to write an integer (signed or unsigned, any size)
+ // to a stream in little-endian order. We swap the byte order before the write if
+ // necessary to always write in little endian order, independantly of the byte
+ // ordering of the compiling machine.
+ template <typename IntType>
+ inline void write_little_endian(std::ostream& stream, IntType value) {
+
+ if (IsLittleEndian)
+ stream.write(reinterpret_cast<const char*>(&value), sizeof(IntType));
+ else
+ {
+ std::uint8_t u[sizeof(IntType)];
+ typename std::make_unsigned<IntType>::type v = value;
+
+ std::size_t i = 0;
+ // if constexpr to silence the warning about shift by 8
+ if constexpr (sizeof(IntType) > 1)
+ {
+ for (; i + 1 < sizeof(IntType); ++i)
+ {
+ u[i] = v;
+ v >>= 8;
+ }
+ }
+ u[i] = v;
+
+ stream.write(reinterpret_cast<char*>(u), sizeof(IntType));
+ }
+ }
+
+ // read_little_endian(s, out, N) : read integers in bulk from a little indian stream.
+ // This reads N integers from stream s and put them in array out.
+ template <typename IntType>
+ inline void read_little_endian(std::istream& stream, IntType* out, std::size_t count) {
+ if (IsLittleEndian)
+ stream.read(reinterpret_cast<char*>(out), sizeof(IntType) * count);
+ else
+ for (std::size_t i = 0; i < count; ++i)
+ out[i] = read_little_endian<IntType>(stream);
+ }
+
+ // write_little_endian(s, values, N) : write integers in bulk to a little indian stream.
+ // This takes N integers from array values and writes them on stream s.
+ template <typename IntType>
+ inline void write_little_endian(std::ostream& stream, const IntType* values, std::size_t count) {
+ if (IsLittleEndian)
+ stream.write(reinterpret_cast<const char*>(values), sizeof(IntType) * count);
+ else
+ for (std::size_t i = 0; i < count; ++i)
+ write_little_endian<IntType>(stream, values[i]);
+ }
+
+} // namespace Stockfish::Eval::NNUE