[rescue] sparc10 cpu - what to do.

Peter Corlett abuse at cabal.org.uk
Wed Dec 21 13:04:00 CST 2016

On Tue, Dec 20, 2016 at 11:46:31AM -0600, Mark Linimon wrote:
> On Tue, Dec 20, 2016 at 03:04:31PM +0100, Peter Corlett wrote:
>> Modern Intel x86-64 chips, if you squint. They read in 120-bit wide
>> "instructions", which consist of up to six x86 instructions which it will
>> attempt to execute in parallel.
> I've wondered what kind of performance boost we could get if we ran directly
> at the microcode layer (the one that pretends it's this obsolete junk).

There's probably not much in it. You lose a bit on the translation from x86
code to micro-ops, but win from having a more compact representation and less
I-cache pressure.

The deal-breaker is that compiler backends would have to be much more complex,
and code would need to be recompiled for each new processor generation. If it
were that simple, we'd all have ARM desktops now.

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