Let me explain using a few extremely simplified examples of things a compiler might do.
Imagine the code
For(int i=0,i<5,i++)
Print i
And then the code
Print 0
Print 1
Print 2
Print 3
Print 4
Some compilers compile things like this into identical byte code. So recreating the original code of the for loop is non trivial.
Yeah, you get what you get on the way back once a compiler tries to optimize things.
There are things called decompilers out there but you don’t really want to rely on them. Like @tabor473 showed, it can be quite messy on the other way around. You would not want to try and re-code it based upon the process. Go ahead and download one of these and see what comes out. You will spend less time redoing your vex program. What you might get are some constant values you worked long and hard to tune.
C decompliers:
What wiki has to say…
There is no decompiler for ROBOTC, a decompiler has to know the type of CPU that the code has been compiled for. As ROBOTC uses a virtual machine (in other words we have created our own CPU in software) the decompiler would have to understand what the ROBOTC instruction set is.