If the OS loads executables by mmap and load on page-hit, you can potentially save memory by not ever loading unused parts of an executable. a transform-on-load requires the entire program to be loaded before execution begins.
Pick a random large process on a linux host - like your web browser. cat /proc/$pid/status.
VmExe is the size of the mapped executable; VmLib is the size of all the other mapped libraries and executable pages. Add those two numbers together to find the size of all the executable code mapped into this binary.
VmRSS is the amount of physical memory that the process is currently using. You'll find that this is a lot smaller than the code mapped into the binary. That's because the kernel hasn't loaded any of that into physical memory.
If there is a perceived error in what I wrote, then, like the one nice responder, explain, please.
HN is such a different community now than when I joined 1,835 days ago. It brings tears to my eyes.