Because C allows functions to have a variable number of parameters, parameters must be pushed onto the stack from right to left. (If parameters were pushed from left to right, it would be difficult for the compiler to determine which parameter was first.) If you do not specify command-line options that modify the function-calling convention, the C calling convention is used; otherwise, the __cdecl keyword must be used before any function using the C calling convention.
If, for example, you use the /Gr (register calling convention) option when you compile, and the function add_two must have the C calling convention, declare add_two as follows:
int __cdecl add_two( int x, int y );