For those of us who use SciTE4AutoIt3 then you would've come across (at some stage) the directive #AutoIt3Wrapper_Res_SaveSource, it allows you to save the script to the compiled exe thus allowing you to retrieve at a later stage, great if you accidentally delete your source file.
_GetSavedSource() allows you to extract the source file from the compiled executable and save to a file of your choice.
Note: You must use #AutoIt3Wrapper_Res_SaveSource=Y at the top of the script for this to