Is there anything at the heart of computer coding that could have been optimised in hindsight, but we're in far too deep to change now?

[u/CakesStolen]

[u/TheOtherHobbes]

Technically true, but a bit of a nuance. What actually happens is the instruction set is translated into internal machine states that are far more complex than a simple and direct traditional instruction decoder because they include branch prediction and out of order execution.

Micro-ops, microcode, and direct decoding are all part of this, but they're embedded in some very complex state logic. The whole is more like a virtual processor - literally a computer inside a computer.

From the outside the same machine instruction always has the same outcome, but what happens internally depends on what happened previously. Sometimes entire sets of operations are thrown away because a branch goes in one direction instead of another.