3 ms·
This is where people usually come in saying that x86 is internally RISC, and that the ISA helps with code density which is otherwise a problem for RISC
by valarauca1 10y ago
This is where people usually come in saying that x86 is
internally RISC, and that the ISA helps with code density
which is otherwise a problem for RISC. Is there any truth
to that?
Yes/No.
Modern x86_64 chips are likely RISC-y in their core post μOP decoding. More-over it is way more complicated then that because port forwarding stalls point to what is presented as a core likely being 15-20 specialized cores working in conjunction. But then Skylake fixed this so who knows.
The RISC instruction density is just a hold over from the 80's when RAM was fast, and decoding was hard.
Modern iCache's + Moore's Law has more or less solved these problems.