[rescue] sparc10 cpu - what to do.

Sandwich Maker adh at an.bradford.ma.us
Tue Dec 20 14:22:04 CST 2016

" On 12/20/2016 12:46 PM, Mark Linimon wrote:
" >> [...] Has there been any VLIW architecture that has been successful as a
" >> general purpose CPU?
" >
" > 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).

" From: Dave McGuire <mcguire at neurotica.com>
"   People have been asking this since the micro-op architecture of the
" PentiumPro was publicized.  Man if we only had access to that level..

i was under the impression that one of the bios blobs was instruction
set patches for buggy cpu versions.  i got this iirc from openbios'
discussion on de-blobbing.

" From: Mouse <mouse at Rodents-Montreal.ORG>
" Significant, probably, but also hellishly complicated to do anything
" useful with.  Risky, too; microcode tends to allow things like gating
" more than one internal register onto an internal data bus at the same
" time.  And probably strictly Harvard, rather than von Neumann.
" And very, very processor-rev-specific.

but a *better* but still portable instruction set could also be
devised to sit above microcode.  porting would then be reduced to
mapping a new microcode to the instruction set.
back at the dawn of the microprocessor stone age, i recall mos
technology offering to customize the 6502's instruction set for
high-volume customers, and i recall thinking - couldn't one get the
compiler to do this?  it would have to know everything microcode could
do as well as the size of the instruction-set memory, in order to
devise the set which would enable the densest, most efficient code.
i was imagining it for high volume embedded-type apps.

yes, comparing the 6502 to modern chips is like comparing a paper dart
to the space shuttle...
Andrew Hay                                  the genius nature
internet rambler                            is to see what all have seen
adh at an.bradford.ma.us                       and think what none thought

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