Re: MISC - Stack Based vs. Register Based

From	glen herrmannsfeldt <gah@ugcs.caltech.edu>
Newsgroups	comp.lang.forth, comp.arch.fpga
Subject	Re: MISC - Stack Based vs. Register Based
Date	2013-04-04 12:44 +0000
Organization	Aioe.org NNTP Server
Message-ID	<kjjsiq$1fl$1@speranza.aioe.org> (permalink)
References	(1 earlier) <kjf48e$5qu$1@dont-email.me> <kjihkv$gdm$1@speranza.aioe.org> <kjin8q$so5$1@speranza.aioe.org> <515d6101$0$6090$e4fe514c@dreader36.news.xs4all.nl> <515d633c$0$6981$e4fe514c@news2.news.xs4all.nl>

Cross-posted to 2 groups.

Show all headers | View raw

In comp.arch.fpga Arlet Ottens <usenet+5@c-scape.nl> wrote:
> On 04/04/2013 01:16 PM, Albert van der Horst wrote:

>>>> You mentioned code density.  AISI, code density is purely a CISC
>>>> concept.  They go together and are effectively inseparable.

>>> They do go together, but I am not so sure that they are inseperable.

>>> CISC began when much coding was done in pure assembler, and anything
>>> that made that easier was useful. (One should figure out the relative
>>> costs, but at least it was in the right direction.)

>> But, of course, this is a fallacy. The same goal is accomplished by
>> macro's, and better. Code densitity is the only valid reason.

> Speed is another valid reason.

Presumably some combination of ease of coding, speed, and also Brooks'
"Second System Effect".

Paraphrasing from "Mythical Man Month" since I haven't read it recently,
the ideas that designers couldn't implement in their first system that
they designed, for cost/efficiency/whatever reasons, come out in the
second system. 

Brooks wrote that more for OS/360 (software) than for S/360 (hardware),
but it might still have some effect on the hardware, and maybe also
for VAX.

There are a number of VAX instructions that seem like a good idea, but
as I understand it ended up slower than if done without the special
instructions.

As examples, both the VAX POLY and INDEX instruction. When VAX was new,
compiled languages (Fortran for example) pretty much never did array
bounds testing. It was just too slow. So VAX supplied INDEX, which in
one instruction did the multiply/add needed for a subscript calcualtion
(you do one INDEX for each subscript) and also checked that the
subscript was in range. Nice idea, but it seems that even with INDEX
it was still too slow.

Then POLY evaluates a whole polynomial, such as is used to approximate
many mathematical functions, but again, as I understand it, too slow.

Both the PDP-10 and S/360 have the option for an index register on
many instructions, where when register 0 is selected no indexing is
done. VAX instead has indexed as a separate address mode selected by
the address mode byte. Is that the most efficient use for those bits?

-- glen

Back to comp.lang.forth | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-03-29 17:00 -0400
  Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-03-29 21:43 +0000
    Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-03-29 20:28 -0400
      Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-03-31 18:34 +0000
        Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-02 09:54 -0400
          Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-04-02 17:20 +0000
            Re: MISC - Stack Based vs. Register Based David Brown <david@westcontrol.removethisbit.com> - 2013-04-03 09:12 +0200
    Re: MISC - Stack Based vs. Register Based Jon Elson <jmelson@wustl.edu> - 2013-04-01 15:11 -0500
  Re: MISC - Stack Based vs. Register Based AKE <assadebrahim2000@gmail.com> - 2013-03-29 18:19 -0700
    Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-03-30 18:50 -0400
      Re: MISC - Stack Based vs. Register Based Jecel <jecel@merlintec.com> - 2013-04-01 13:18 -0700
        Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-02 10:50 -0400
          Re: MISC - Stack Based vs. Register Based Jecel <jecel@merlintec.com> - 2013-04-02 23:39 -0700
            Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-03 09:54 -0400
              Re: MISC - Stack Based vs. Register Based Jecel <jecel@merlintec.com> - 2013-04-05 14:30 -0700
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-05 17:53 -0400
                Re: MISC - Stack Based vs. Register Based Jecel <jecel@merlintec.com> - 2013-04-06 13:27 -0700
                Re: MISC - Stack Based vs. Register Based Jecel <jecel@merlintec.com> - 2013-04-06 13:37 -0700
        Re: MISC - Stack Based vs. Register Based Paul Rubin <no.email@nospam.invalid> - 2013-04-07 15:21 -0700
          Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-08 01:24 -0400
            Re: MISC - Stack Based vs. Register Based Syd Rumpo <usenet@nononono.co.uk> - 2013-04-08 10:18 +0100
          Re: MISC - Stack Based vs. Register Based Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-04-08 04:18 -0500
  Re: MISC - Stack Based vs. Register Based Arlet Ottens <usenet+5@c-scape.nl> - 2013-03-30 08:20 +0100
    Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-03-30 19:00 -0400
      Re: MISC - Stack Based vs. Register Based Arlet Ottens <usenet+5@c-scape.nl> - 2013-03-31 13:20 +0200
  Re: MISC - Stack Based vs. Register Based "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-03-30 17:54 -0400
    Re: MISC - Stack Based vs. Register Based Arlet Ottens <usenet+5@c-scape.nl> - 2013-03-31 09:11 +0200
      Re: MISC - Stack Based vs. Register Based "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-04-01 20:10 -0400
        Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-04-02 00:54 +0000
          Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-02 13:31 -0400
            Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-04-02 19:03 +0000
        Re: MISC - Stack Based vs. Register Based Arlet Ottens <usenet+5@c-scape.nl> - 2013-04-02 08:25 +0200
          Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-02 13:33 -0400
        Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-02 13:26 -0400
          Re: MISC - Stack Based vs. Register Based "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-04-03 20:34 -0400
            Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-04-04 02:07 +0000
              Re: MISC - Stack Based vs. Register Based albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-04-04 11:16 +0000
                Re: MISC - Stack Based vs. Register Based Arlet Ottens <usenet+5@c-scape.nl> - 2013-04-04 13:25 +0200
                Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-04-04 12:44 +0000
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-04 17:04 -0400
                Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-04-04 21:34 +0000
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-04 19:30 -0400
                Re: MISC - Stack Based vs. Register Based Mark Wills <markrobertwills@yahoo.co.uk> - 2013-04-05 00:41 -0700
                Re: MISC - Stack Based vs. Register Based Alex McDonald <blog@rivadpm.com> - 2013-04-04 15:30 -0700
                Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-04-04 23:15 +0000
                Re: MISC - Stack Based vs. Register Based Alex McDonald <blog@rivadpm.com> - 2013-04-04 17:26 -0700
                Re: MISC - Stack Based vs. Register Based albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-04-05 01:17 +0000
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-05 18:00 -0400
                Re: MISC - Stack Based vs. Register Based "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-04-08 23:55 -0400
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-04 20:07 -0400
                Re: MISC - Stack Based vs. Register Based Mark Wills <markrobertwills@yahoo.co.uk> - 2013-04-05 00:51 -0700
                Re: MISC - Stack Based vs. Register Based Arlet Ottens <usenet+5@c-scape.nl> - 2013-04-05 14:31 +0200
                Re: MISC - Stack Based vs. Register Based Mark Wills <markrobertwills@yahoo.co.uk> - 2013-04-05 07:33 -0700
                Re: MISC - Stack Based vs. Register Based Arlet Ottens <usenet+5@c-scape.nl> - 2013-04-05 17:01 +0200
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-05 18:25 -0400
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-06 17:44 -0400
                Re: MISC - Stack Based vs. Register Based Brad Eckert <hwfwguy@gmail.com> - 2013-04-05 10:14 -0700
                Re: MISC - Stack Based vs. Register Based Arlet Ottens <usenet+5@c-scape.nl> - 2013-04-05 20:13 +0200
                Re: MISC - Stack Based vs. Register Based Arlet Ottens <usenet+5@c-scape.nl> - 2013-04-05 20:15 +0200
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-05 18:54 -0400
                Re: MISC - Stack Based vs. Register Based Brad Eckert <hwfwguy@gmail.com> - 2013-04-08 09:57 -0700
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-09 10:13 -0400
                Re: MISC - Stack Based vs. Register Based Brad Eckert <hwfwguy@gmail.com> - 2013-04-09 08:55 -0700
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-09 14:40 -0400
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-05 18:49 -0400
                Re: MISC - Stack Based vs. Register Based daveyrotten <danw8804@gmail.com> - 2013-04-09 13:02 -0700
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-09 16:07 -0400
                Re: MISC - Stack Based vs. Register Based daveyrotten <danw8804@gmail.com> - 2013-04-09 13:26 -0700
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-10 00:33 -0400
                Re: MISC - Stack Based vs. Register Based daveyrotten <danw8804@gmail.com> - 2013-04-10 07:08 -0700
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-10 10:13 -0400
                Re: MISC - Stack Based vs. Register Based Sieur de Bienville <morrimichael@gmail.com> - 2013-04-10 21:08 -0700
                Re: MISC - Stack Based vs. Register Based Paul Rubin <no.email@nospam.invalid> - 2013-04-10 22:47 -0700
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-11 16:32 -0400
                Re: MISC - Stack Based vs. Register Based "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-04-18 06:23 -0400
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-18 17:06 -0400
                Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-04-05 17:33 +0000
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-06 17:37 -0400
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-05 18:08 -0400
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-06 17:32 -0400
                Re: MISC - Stack Based vs. Register Based Brian Davis <brimdavis@aol.com> - 2013-04-07 14:59 -0700
                Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-08 01:16 -0400
                Re: MISC - Stack Based vs. Register Based albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-04-08 09:52 +0000
            Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-03 22:42 -0400
            Re: MISC - Stack Based vs. Register Based Alex McDonald <blog@rivadpm.com> - 2013-04-04 16:07 -0700
              Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-04-05 04:10 +0000
                Re: MISC - Stack Based vs. Register Based Alex McDonald <blog@rivadpm.com> - 2013-04-04 23:49 -0700
    Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-02 12:04 -0400
      Re: MISC - Stack Based vs. Register Based "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-04-03 20:35 -0400
        Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-04 00:09 -0400
  Re: MISC - Stack Based vs. Register Based the_gavino_himself <visphatesjava@gmail.com> - 2013-04-02 11:17 -0700
  Re: MISC - Stack Based vs. Register Based Syd Rumpo <usenet@nononono.co.uk> - 2013-04-04 09:38 +0100
    Re: MISC - Stack Based vs. Register Based Arlet Ottens <usenet+5@c-scape.nl> - 2013-04-04 11:31 +0200
      Re: MISC - Stack Based vs. Register Based "Elizabeth D. Rather" <erather@forth.com> - 2013-04-04 08:36 -1000
        Re: MISC - Stack Based vs. Register Based Brad Eckert <hwfwguy@gmail.com> - 2013-04-05 10:21 -0700
          Re: MISC - Stack Based vs. Register Based "Elizabeth D. Rather" <erather@forth.com> - 2013-04-05 07:53 -1000
    Re: MISC - Stack Based vs. Register Based glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-04-04 12:49 +0000
      Re: MISC - Stack Based vs. Register Based Arlet Ottens <usenet+5@c-scape.nl> - 2013-04-04 15:02 +0200
    Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-04 18:57 -0400
  Re: MISC - Stack Based vs. Register Based AKE <assadebrahim2000@gmail.com> - 2013-04-05 15:29 -0700
    Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-05 19:32 -0400
      Re: MISC - Stack Based vs. Register Based anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-04-06 14:16 +0000
        Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-06 15:50 -0400
          Re: MISC - Stack Based vs. Register Based mhx@iae.nl (Marcel Hendrix) - 2013-04-07 01:33 +0200
            Re: MISC - Stack Based vs. Register Based AKE <assadebrahim2000@gmail.com> - 2013-04-07 02:57 -0700
              Re: MISC - Stack Based vs. Register Based stephenXXX@mpeforth.com (Stephen Pelc) - 2013-04-07 11:02 +0000
              Re: MISC - Stack Based vs. Register Based anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-04-07 13:51 +0000
                Re: MISC - Stack Based vs. Register Based "Elizabeth D. Rather" <erather@forth.com> - 2013-04-07 09:16 -1000
            Re: MISC - Stack Based vs. Register Based anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-04-07 14:13 +0000
              Re: MISC - Stack Based vs. Register Based mhx@iae.nl (Marcel Hendrix) - 2013-04-07 17:14 +0200
                Re: MISC - Stack Based vs. Register Based anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-04-07 15:31 +0000
            Re: MISC - Stack Based vs. Register Based Bernd Paysan <bernd.paysan@gmx.de> - 2013-04-08 18:53 +0200
          Re: MISC - Stack Based vs. Register Based anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-04-07 14:22 +0000
  Re: MISC - Stack Based vs. Register Based "WJ" <w_a_x_man@yahoo.com> - 2013-04-14 00:19 +0000
    Re: MISC - Stack Based vs. Register Based rickman <gnuarm@gmail.com> - 2013-04-14 09:44 -0400
    Re: MISC - Stack Based vs. Register Based Brad Eckert <hwfwguy@gmail.com> - 2013-04-15 09:39 -0700
      Re: MISC - Stack Based vs. Register Based Bernd Paysan <bernd.paysan@gmx.de> - 2013-04-15 19:28 +0200

csiph-web