In theory, perhaps. In the real world, there is always a tradeoff between optimizing the last bit of performance into something, and the cost thereof. The microcode compilers I have used have done a better job that a person would have done in any practical length of time that a company would have been willing to pay for. Tony's example of trying to figure out which way AMUX should be set is exactly the sort of thing that a proper microcode compiler takes care of. Note that my idea of a compiled language for microcode and his for an assembler are actually quite close. I don't call it an assembler because there isn't a simple correspondence between source "statements" and microinstruction words, and my compiler handles algebraic expressions, loops, and various control structures. On the other hand, there have been some so-called "assemblers" that do that also. The dividing line between assemblers and compilers has always been somewhat vague, and it has gotten worse in recent years since now assemblers for RISC machines are expected to do instruction scheduling. And then there is VLIW and EPIC...