Re: x86S Specification

On Mon, 21 Oct 2024 22:02:27 +0000, BGB wrote:

On 10/17/2024 4:34 PM, EricP wrote:

Say, if one could make the CPU itself have 35% more perf/W by jumping to
a different encoding scheme, this could easily offset if they needed to
pay a 20% cost by JIT compiling everything when running legacy
software...

This only works when the mative ISA has a direct path to emulating
the address modes of x86-64 which includes [Rbase+Rindex<<scale+DISP]
It is also a hopelessly frail path to self destruction:: Transmeta.

Granted, this is predicated on the assumption that one could get such a
jump by jumping to a different encoding scheme.

It is not the encoding scheme that is kaput, it is the semantics
such a scheme provides the programmer via ISA.
--------------------------------

The major selling point of x86 has been its backwards compatibility, but
this advantage may be weakening with the rise of the ability to emulate
stuff at near native performance. If Windows could jump ship and provide
an experience that "doesn't suck" (fast/reliable/transparent emulation
of existing software), the main advantages of the x86-64 legacy may go
away (and is already mostly moot in Linux since the distros typically
recompile everything from source, with little real/significant ties to
the x86 legacy).

W11 has done enough to my day-to-day operations I am willing to
jump ship to Linux in order to avoid daily updates an the myriad
of technical issues that never seem to get solved in a way that
makes then "go away" forever. So, for me it is not that it will
be an x86 (or ARM, or ...) it is that it is not MS oriented.