local mov

In assembly language programming, the function prologue is a few lines of code which appear at the beginning of a function, which prepare the stack and registers for use within the function. Similarly, the function epilogue appears at the end of the function, and restores the stack and registers back to the state they were in before the function was called.

The prologue and epilogue are not a part of the assembly language itself - rather, they represent a convention used by assembly language programmers, and compilers of many higher-level languages. Both of them are fairly rigid, having the same form in each function.

Prologue

The function prologue typically does the following actions (Note this procedure may differ from one architecture to another):

Note that several possible prologues can be written, resulting in slightly different stack configuration. These differences are acceptable, as long as the programmer or compiler uses the stack in the correct way inside the function.