There’s a sayings, the C language was developed to compile for the PDP-11. In the meantime much has happened. So Modern processors were designed to seamlessly

There’s a sayings, the C language was developed to compile for the PDP-11. In the meantime much has happened. So Modern processors were designed to seamlessly run existing software. For example Memory used to be fated the processors clock cycles so fetches were free. Now it’s 100x slower. So we put caches in to fool the software into thinking it’s just as fast as it used to be. So all software runs in a bubble like it was still running on a PDP-11. Just like the body continues to carry around a liquid environment with a salinity level equal to the ancient ocean.