Fastest way to convert int to 4 bytes in C#

Question

What is a fastest way to convert int to 4 bytes in C# ?

Fastest as in execution time not development time.

My own solution is this code:

byte[] bytes = new byte[4]; unchecked {  bytes[0] = (byte)(data >> 24);  bytes[1] = (byte)(data >> 16);  bytes[2] = (byte)(data >> 8);  bytes[3] = (byte)(data); } 

Right now I see that my solution outperforms both struct and BitConverter by couple of ticks.

I think the unsafe is probably the fastest option and accept that as an answer but I would prefer to use a managed option.

Answer 1

A byte* cast using unsafe code is by far the fastest:

    unsafe static void Main(string[] args) {         int i = 0x12345678;         byte* pi = (byte*)&i;         byte lsb = pi[0];           // etc..     } 

That's what BitConverter does as well, this code avoids the cost of creating the array.