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Groups > comp.lang.forth > #49543
| From | anton@mips.complang.tuwien.ac.at (Anton Ertl) |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: Forth coding style vs "Algol et al" coding style |
| Date | 2016-07-26 16:51 +0000 |
| Organization | Institut fuer Computersprachen, Technische Universitaet Wien |
| Message-ID | <2016Jul26.185140@mips.complang.tuwien.ac.at> (permalink) |
| References | (2 earlier) <8fc90f76-ca06-498d-b12a-603ea8647079@googlegroups.com> <2159c4c3-114b-42a0-b04c-3efb928679fc@googlegroups.com> <gaydnaCaveOqOR7KnZ2dnUU7-amdnZ2d@supernews.com> <81c72add-bac3-4c44-a873-0d7d71d9d80e@googlegroups.com> <nn6bhm$pju$1@dont-email.me> |
Bernd Paysan <bernd.paysan@gmx.de> writes:
>Am Tue, 12 Jul 2016 15:59:11 -0700 schrieb lawrencedo99:
>> I think the 680x0 family were definitely inspired by the PDP-11.
>
>Indeed.
The PDP-11 certainly was very influential, but the 68000 was not
particularly strongly inspired by it. In particular, the 68000 does
not have general-purpose registers, which was one of the major changes
of the PDP-11 compared to the PDP-8 (and the PDP-8 offspring and
competing design which later became the DG Nova); instead the 68000
has data and address registers, i.e., accumulators and index
registers; so it's a generalized accumulator architecture rather than
a register architecture. Maybe the CDC-6600 (also a generalized
register architecture) had more of an influence on the 68000
architecture than the PDP-11.
>> One nice thing about the original 68000: even thought it was classed as
>> a "16-bit" chip, it was very clearly a cut-down 32-bit design.
>> Unfortunately, this hurt its performance in the short term, compared to
>> Intel x86 and others.
>
>No, performance wasn't the problem. According to this FAQ, the 8MHz 68k
>had 2100 dhrystones (other reports show lower scores; this, after all, is
>also a compiler issue), while an 8088 had just ~300, and a 10MHz 286 had
>1889, still less than the 68k at 8MHz.
>
>http://www.faqs.org/faqs/motorola/68k-chips-faq/
The benchmark results I saw at the time mostly reported the 80286 to
be faster then the 68000. Looking at the cycle counts (e.g.,
<http://zsmith.co/intel_a.html#add>,
<https://wiki.neogeodev.org/index.php?title=68k_instructions_timings>:
(d)reg += (d)reg is 2 cycles on the 80286, 8 cycles on the 68000
(d)reg += mem is 7 cycles on the 80286, 8(BW)-14(L) cycles on the 68000
mem += (d)reg is 7 cycles on the 80286, 12(BW)-20(L) cycles on the 68000
Sure, you can save some instructions and some memory accesses on the
68000 by keeping things in registers or by using autoincrement, but
that will usually not make up for such big differences in cycle
counts.
>The primary reason these CISC processors weren't very fast was that they
>all used microcode, and couldn't do single cycle instructions (the 68k
>needed 4 cycles for simple instructions). The early RISC with similar
>die size ran a lot faster.
Apart from the IBM 801 (1980, but probably not a single chip, and not
a product anyway), they all came quite a bit later, 1985 and later.
The 386 (1985) had similar cycle counts as the 286; single-cycle
instructions were achieved by Intel with the 486 (1989) and Motorola
with the 68040 (1990).
Maybe, if the RISC design principles had been developed and
disseminated already in 1976, the 68000 design team (which did not go
for software compatibility, unlike Intel) might have designed
something more RISC-like (although probably with 16-bit instructions);
the 68000 had a similar number of transistors (40000 according to
<https://en.wikipedia.org/wiki/Motorola_68000#History>) as the ARM1
(25000), was manufactured in a similar-sized process (3.5um vs. 3um)
and had a similar area (44mm^2 vs. 50mm^2), so it should have been
possible. They might also have been faster in completing their
design.
- anton
--
M. Anton Ertl http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
New standard: http://www.forth200x.org/forth200x.html
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Forth coding style vs "Algol et al" coding style foxaudioresearch@gmail.com - 2016-07-08 17:44 -0700
Re: Forth coding style vs "Algol et al" coding style "WJ" <w_a_x_man@yahoo.com> - 2016-07-09 04:27 +0000
Re: Forth coding style vs "Algol et al" coding style humptydumpty <ouatubi@gmail.com> - 2016-07-09 10:30 -0700
Re: Forth coding style vs "Algol et al" coding style Julian Fondren <julian.fondren@gmail.com> - 2016-07-09 21:56 -0700
Re: Forth coding style vs "Algol et al" coding style mhx@iae.nl - 2016-07-10 00:30 -0700
Re: Forth coding style vs "Algol et al" coding style mhx@iae.nl - 2016-07-10 00:34 -0700
Re: Forth coding style vs "Algol et al" coding style foxaudioresearch@gmail.com - 2016-07-10 09:10 -0700
Re: Forth coding style vs "Algol et al" coding style endlessboomcapitalism@gmail.com - 2016-07-12 18:55 -0700
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-10 01:39 -0700
Re: Forth coding style vs "Algol et al" coding style foxaudioresearch@gmail.com - 2016-07-10 08:50 -0700
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-10 15:00 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-10 22:53 -0400
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-11 01:59 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-11 09:44 -0400
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-11 10:51 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-11 15:26 -0400
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-12 15:18 -0700
Re: Forth coding style vs "Algol et al" coding style foxaudioresearch@gmail.com - 2016-07-25 19:56 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-25 23:13 -0400
Re: Forth coding style vs "Algol et al" coding style jim.brakefield@ieee.org - 2016-07-26 07:34 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-26 11:23 -0400
Re: Forth coding style vs "Algol et al" coding style jim.brakefield@ieee.org - 2016-07-26 13:18 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-26 18:14 -0400
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-27 02:43 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-27 10:24 -0400
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-27 02:46 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-27 10:26 -0400
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-27 02:53 -0700
Re: Forth coding style vs "Algol et al" coding style foxaudioresearch@gmail.com - 2016-07-27 08:32 -0700
Re: Forth coding style vs "Algol et al" coding style foxaudioresearch@gmail.com - 2016-07-27 09:04 -0700
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-28 02:05 -0700
Re: Forth coding style vs "Algol et al" coding style foxaudioresearch@gmail.com - 2016-07-28 06:27 -0700
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-29 03:01 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-30 02:28 -0400
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-11 13:05 -0400
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-11 10:47 -0700
Re: Forth coding style vs "Algol et al" coding style Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-07-11 08:50 -0500
Re: Forth coding style vs "Algol et al" coding style Michael Barry <barrym95838@yahoo.com> - 2016-07-11 08:23 -0700
Re: Forth coding style vs "Algol et al" coding style Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-07-11 11:48 -0500
Re: Forth coding style vs "Algol et al" coding style Cecil Bayona <cbayona@cbayona.com> - 2016-07-11 12:16 -0500
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-11 10:38 -0700
Re: Forth coding style vs "Algol et al" coding style Cecil Bayona <cbayona@cbayona.com> - 2016-07-11 13:32 -0500
Re: Forth coding style vs "Algol et al" coding style Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-07-11 12:45 -0500
Re: Forth coding style vs "Algol et al" coding style Brad Eckert <hwfwguy@gmail.com> - 2016-07-11 11:49 -0700
Re: Forth coding style vs "Algol et al" coding style Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-07-12 05:02 -0500
Re: Forth coding style vs "Algol et al" coding style Michael Barry <barrym95838@yahoo.com> - 2016-07-11 14:22 -0700
Re: Forth coding style vs "Algol et al" coding style Cecil Bayona <cbayona@cbayona.com> - 2016-07-11 16:31 -0500
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-12 15:31 -0400
Re: Forth coding style vs "Algol et al" coding style lawrencedo99@gmail.com - 2016-07-12 15:55 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-25 22:48 -0400
Re: Forth coding style vs "Algol et al" coding style lawrencedo99@gmail.com - 2016-08-10 01:54 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-08-21 19:32 -0400
Re: Forth coding style vs "Algol et al" coding style lawrencedo99@gmail.com - 2016-08-28 22:55 -0700
Re: Forth coding style vs "Algol et al" coding style hughaguilar96@gmail.com - 2016-08-29 00:34 -0700
Re: Forth coding style vs "Algol et al" coding style Howerd <howerdo@yahoo.co.uk> - 2016-07-11 11:58 -0700
Re: Forth coding style vs "Algol et al" coding style lawrencedo99@gmail.com - 2016-07-12 15:59 -0700
Re: Forth coding style vs "Algol et al" coding style Bernd Paysan <bernd.paysan@gmx.de> - 2016-07-26 00:40 +0000
Re: Forth coding style vs "Algol et al" coding style "Elizabeth D. Rather" <erather@forth.com> - 2016-07-25 21:16 -1000
Re: Forth coding style vs "Algol et al" coding style Bernd Paysan <bernd.paysan@gmx.de> - 2016-08-21 23:04 +0000
Re: Forth coding style vs "Algol et al" coding style Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-07-26 03:34 -0500
Re: Forth coding style vs "Algol et al" coding style Bernd Paysan <bernd.paysan@gmx.de> - 2016-08-21 23:13 +0000
Re: Forth coding style vs "Algol et al" coding style anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-07-26 16:51 +0000
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-26 13:51 -0400
Re: Forth coding style vs "Algol et al" coding style Bernd Paysan <bernd.paysan@gmx.de> - 2016-08-21 23:38 +0000
Re: Forth coding style vs "Algol et al" coding style anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-08-22 12:51 +0000
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-25 22:50 -0400
Re: Forth coding style vs "Algol et al" coding style Brad Eckert <hwfwguy@gmail.com> - 2016-07-26 16:32 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-27 10:19 -0400
Re: Forth coding style vs "Algol et al" coding style "Elizabeth D. Rather" <erather@forth.com> - 2016-07-27 09:05 -1000
Re: Forth coding style vs "Algol et al" coding style lawrencedo99@gmail.com - 2016-07-12 15:51 -0700
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-14 03:34 -0700
Re: Forth coding style vs "Algol et al" coding style rickman <gnuarm@gmail.com> - 2016-07-25 22:51 -0400
Re: Forth coding style vs "Algol et al" coding style Mark Wills <markwills1970@gmail.com> - 2016-07-11 01:56 -0700
Re: Forth coding style vs "Algol et al" coding style foxaudioresearch@gmail.com - 2016-07-11 08:03 -0700
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