The opposite is increasingly true, too - micro-op and macro-op fusion joins multiple instructions into one.

There's no clear-cut line no more.

The implementations may have converged but there's still hard differences in the ISA. RISC (including ARM) has fixed-width instructions, x86 has variable width. RISC (including ARM again) is load-store, x86 allows memory to be sources or destinations. So ARM can have simpler decoder logic, if nothing else.

Sure, but it's not true that CISC machines are just proxies to RISC ones.

> no more ?

I can't remember there being a clean line for decades now.

> Newer Intel CPUs are even using RISC cores with wrappers for CISC functions because it is more efficient.

Not even newer chips. The Pentium Pro was released in what, 1996?

> Newer Intel CPUs are even using RISC cores with wrappers for CISC functions because it is more efficient.

this has been going on for quite a while now, iirc approx 20 years or thereabouts...

And x86 started ~20 years before that? Thanks for the info though.

Not only that—when people speak of ARM vs. x86, they aren't really talking about the instruction sets at all—they're talking about the processor lines that have been developed and evolved over period of many years.