I think it’s the language. Haven’t really tested but in C# that would be something like that, 8 lines of code instead of 40: public static byte[] func( uin

I think it’s the language. Haven’t really tested but in C# that would be something like that, 8 lines of code instead of 40: public static byte[] func( uint p, uint q ) { int pw = 32 - BitOperations.LeadingZeroCount( p ); int qw = 32 - BitOperations.LeadingZeroCount( q ); Span<byte> buff = stackalloc byte[ 9 ]; ulong val = (ulong)q | (ulong)p << qw; BinaryPrimitives.WriteUInt64BigEndian( buff.Slice( 1 ), val ); int totalBytes = ( pw + qw + 7 ) / 8; buff[ 8 - totalBytes ] = (byte)qw; return buff.Slice( 8 - totalBytes ).ToArray(); } In C++ about the same, albeit you gonna need either C++/20 language version, or some non-standard compiler specific intrinsics for bit scan and byte swap.