I liked the first few paragraphs, but the article took a wrong turn for me when it pivoted to ir. Compiler ir need not be fiendishly complex, though modern compilers, particularly clang and gcc can create this impression.

There are two nice benchmarks that I use to measure the complexity of a compiler: how long is the compiler and how long does it take to self compile. Clang and gcc are abysmal on these benchmarks. In fact, I would argue that they fail the second benchmark entirely because they are not capable of self compilation because their build systems rely on external tooling. In other words, there is no implementation of gcc or clang that does not rely on an additional tool that is external to the compiler itself.

The main pedagogical value of these compilers is not as an exemplar, but rather an antithesis.