Comment by saagarjha

(Disclaimer: I don't design ISAs) This goes over a decent amount of nuance that is often lost in internet arguments over ISA design. I frequently hear (on other sites of course, nobody here would be stupid enough to argue this) people going "RISC-V is the best because it has the simplest decode" or "x86-64 has an easy way to do this kind of conditional branch" and everyone is just talking about some facet of the problem without really thinking about the broader picture. Or, worse, they actually have no idea what the problems are for other people, so they'll wave away serious problems in ares they're not familiar with: "oh we can just fuse the uops on big cores", "decoders don't actually matter these days", "nobody will emit that sequence so it doesn't matter if it's fast". To be fair, a lot of the actual practical results are not disclosed widely by the people who make the decisions, so it's easy to fool yourself into whatever you want to believe without the numbers to back it up.