4 ms·
I don't think it's that different. Microcode can work efficiently with multiple ISAs. In practice, x86 and amd64 are actually fairly different targets. With amd
by gridlockd 7y ago
I don't think it's that different. Microcode can work efficiently with multiple ISAs. In practice, x86 and amd64 are actually fairly different targets. With amd64 you have far more registers and no x87 weirdness, for instance. ARM chips also generally support multiple ISAs.
Of course you have trade offs regarding optimizations, but that's true at multiple levels. For example, many exotic x86 instructions (like BCD) aren't as optimized as they could be.
> If you had proposed adding hardware acceleration to make emulation of a specific architecture faster then maybe one could have squinted and said it's emulation instead of secretly implementing a x86 CPU in your ARM CPU.
Of course I'm talking about hardware-level support. I'm talking about the things that already exist.