[Info-vax] CPU architectures, was: Re: problem with 64-bit pointers in C

[Kerry Main]

> -----Original Message-----
> From: Info-vax [mailto:info-vax-bounces at rbnsn.com] On Behalf Of
> already5chosen--- via Info-vax
> Sent: February 13, 2018 8:00 AM
> To: info-vax at rbnsn.com
> Cc: already5chosen at yahoo.com
> Subject: Re: [Info-vax] CPU architectures, was: Re: problem with
64-bit
> pointers in C
> 
> On Tuesday, February 13, 2018 at 11:35:37 AM UTC+2, Jan-Erik
> Soderholm wrote:
> > Den 2018-02-13 kl. 09:27, skrev Simon Clubley:
> > > On 2018-02-13, Jan-Erik Soderholm <jan-erik.soderholm at telia.com>
> wrote:
> > >> Den 2018-02-13 kl. 07:36, skrev Simon Clubley:
> > >>>
> > >>> Those code size changes from VAX to Alpha were not helped by
> the lousy
> > >>> code density on Alpha when compared to VAX.
> > >>
> > >> But that was not a mistake in the Alpha part, that is a known and
> > >> predictable difference between CISC and RISC. You get higher
> speed
> > >> instead due to a "cleaner" architecture.
> > >>
> > >> And as the hardware and memory development has been, code
> density
> > >> has hardly been an issue as such.
> > >>
> > >
> > > I am currently operating under somewhat different memory
> constraints
> > > for my Macro-32 and Macro-64 code. :-)
> > >
> >
> > But you refered to the "lousy code density on Alpha".
> >
> > Your specific needs are probably not a valid benchmark to
> > evalute processor architectures against. :-)
> >
> > >>>
> > >>> Macro-32 is a much nicer assembly language than Macro-64 is.
> > >>>
> > >>
> > >> For the same reason, a CISC environment does more with fewer
> > >> instructions. Also a know effect from RISC, to get higher speed.
> > >>
> > >
> > > This is somewhat architecture specific, even on RISC. ARM is a
much
> > > nicer architecture to write assembly language for than Alpha.
> >
> > ARM was to a higher degree designed for assembled programming.
> > Then in later days ARM has grown higher up into areas where other
> > processorn (such as Alpha) had made its living. And in the same
> > way, Alpha was designed no as much for assembler programming,
> > but for efficient compiler designs and high speed.
> >
> > >
> > >> And at the same time, you where expected to switch from
> assembler
> > >> to higher lever languages. And if I'm not wrong, it is easier to
> > >> design a good compiler on a cleaner architecture (like Alpha).
> > >>
> > >
> > > Alpha is cleaner than x86 (and hence writing compilers for Alpha
is
> > > easier) but VAX was also a clean architecture when it came to
> > > writing compilers.
> > >
> >
> > Of course it helps to write assembler on a very-CISC architecture,
> > since each instruction does more. But with the expense of speed
> > (at that time).
> >
> > Today, even x86 has got some steorids to get up in speed in a way
> > that was not predicable 15-20 years ago.
> 
> It was easily predictable 15-20 years ago.
> Pentium Pro is 22 y.o. and it clearly showed the way to anybody
willing to
> see.
> Exactly 20 years ago is when Intel released 2nd-generation Pentium-II
> that demonstrated that fast x86 is not just possible technically, but
could
> be manufactured cheaply and does not have to consume a lot of power.
> And 18.5 years ago AMD demonstrated that it's possible to design fast
> x86 without multi-billion budget.
> 
[snip...]

Re:  " demonstrated that fast x86 is not just possible technically, but
could
> be manufactured cheaply and does not have to consume a lot of power."

Notwithstanding a little help to Intel from some "friends" in the Alpha
community.  

<
http://www.nytimes.com/1997/10/28/business/intel-and-digital-settle-laws
uit-and-make-deal.html>
"Ending five months of bitter legal wrangling, the Intel Corporation has
agreed to buy the semiconductor manufacturing operations of the Digital
Equipment Corporation for $700 million and to pay royalties to the
computer maker as part of a broad settlement of a patent infringement
suit brought by Digital."


Regards,

Kerry Main
Kerry dot main at starkgaming dot com