What is "__cdecl"?
c++, visual-c++
Solution
`__cdecl` is a calling convention, but the problem you have is a linker failure. It is stating that a definition for the function called `BTM()` cannot be located.
Ensure you are linking with all the necessary `.lib`s.
Problem
I want to use the AES algorithm with MPI. I code in visual c++. When I compile the code I get this error: unresolved external symbol "void __cdecl BTM(int,int)" (?BTM@@YAXHH@Z) referenced in function _main