.globl  fct

fct:    MOVE.L 4(SP), D0
        ADD.L #1,D0
        RTS

| parameters can be addressed via the stack pointer SP
| [SP itself pionts to the return address, so]
| assuming 4 byte values like int or float:
| SP+4 points to the first parameter,
| SP+8 points to the second parameter, and so on
| the function's return value is always passed in D0

