IA64 had a glaring fault that trumps all of it’s advantages. It was explicitly a vliw design, so the user had to, or compiler, manually set multiple different k

IA64 had a glaring fault that trumps all of it’s advantages. It was explicitly a vliw design, so the user had to, or compiler, manually set multiple different kind of ops per single instructions. Modern superscalar OoO is pretty much like that, except there is a piece of hardware internally that does it, almost like a hardware jitter. This freedom both means the magical compiler doesn’t have to exist but also it allows processors to have varying amount of execution units. See that you could actually use one more int alu? Just add it and even older software is able to automatically get the benefit.