A while ago I concluded that this was one of the core conceptual issues with EPIC/VLIW designs that try to shift microcoding to the compiler. It's not that it's

A while ago I concluded that this was one of the core conceptual issues with EPIC/VLIW designs that try to shift microcoding to the compiler. It's not that it's impossible, but there is an advantage to having the microcode layer completely hidden. It frees the CPU core engineers almost completely from having to remain backward compatible with the software that runs on the chip. At present I think of CISC instruction sets like X64 as something like a custom compression codec for the instruction stream. They're not an optimal codec but they're not too bad.