Sujet : Re: Itanium support is back in GCC 15
De : jgd (at) *nospam* cix.co.uk (John Dallman)
Groupes : comp.os.vmsDate : 08. Nov 2024, 23:17:39
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <memo.20241108221703.16100Q@jgd.cix.co.uk>
References : 1
In article <
lp6284Fll3cU1@mid.individual.net>,
gerard.calliet@pia-sofer.fr (gcalliet) wrote:
About Itanium, who knows? I heard about some specific uses of
Itanium. So perhaps a very little business with Itanium could exist
sometime.
It can't last now. There are a finite supply of Itanium CPUs and no more
being made.
On my side I have always thought the failure of Itanium - they said
Itanic - have been just the bad meeting between the conservatism of
geeks and the inchoate laws of the market.
It also had fundamental technical flaws. The basic idea of EPIC, that a
compiler with plenty of time to plan, can optimise memory advance loads
to make Out-of-Order execution unnecessary, is wrong.
It would be possible to do that in a single-core system with no processor
caches, a single-tasking operating system, and few interrupts going off.
In a multi-processor, multi-tasking system which is taking interrupts, it
is impossible to know in advance what data will be in which cache levels,
and hence to optimise memory access in advance.
John