In Win64, there is only one calling convention.

In Win64, there is only one calling convention. The following is an example of passing 4 integer types through a register:
*RCX: First parameter
*RDX: Second parameter
*R8: A third parameter
*R9: Fourth parameter
the 4 integers at the beginning of the argument are passed to the stack. When passing a floating-point parameter, the XMMO-XMM3 register is used.

The calling convention simplifies: all use __fastcall, the first four parameters with RCX, RDX, R8 and R9 Pass, in addition to these four plus rax, R10, R11, other registers are non-volatile.

In Win64, there is only one calling convention.