Library creation with XC8 compiler

Hello,
 
I am stuck on a topic and I hope that someone can help me :)
 
Summarizing, I have a project for a PIC16F18876 microcontroller and I want to update it replacing some sources with a library.
 
What I have done:
- creation of a new library project with the sources that I want to add in the library (basically the whole driver layer);
- updating of the project, removing all the sources already integrated in the library and adding of the .lpp library file in the project. 
 
At this point I have built the new project with the library, the building process is successfully terminated, but the hex file is different from the original project (without the library).
 
I've checked the outputs of the build process (.p1, ecc) and they are the same. 
 
Where is the problem? The Linker?
What I have to do to get the same .hex?
 
Thanks in advance.
 
Carlo
 
 

carlo_87At this point I have built the new project with the library, the building process is successfully terminated, but the hex file is different from the original project (without the library).

 
Why are you surprised by that? You have changed the structure of the code.
 

I've checked the outputs of the build process (.p1, ecc) and they are the same. 
 
Where is the problem?

 
There is no problem so far.
 

The Linker?
What I have to do to get the same .hex?

 
Almost impossible.
 
Have you thought to actually try running the new .hex in hardware?
 

If that was a mandatory outcome, I would never said yes to that job.  Get the same functionality?  That is a "can do". Match the hex???????????

carlo_87
Anyway same compiler version, no changes of the code 

 
You HAVE changed the code.
 
All the right op-codes, but in the wrong order. With apologies to the late Eric Morecambe,