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Re: Stack Sizes

From Walter Banks <walter@bytecraft.com>
Newsgroups comp.lang.forth
Subject Re: Stack Sizes
Date 2016-10-04 10:36 -0400
Organization Aioe.org NNTP Server
Message-ID <nt0epk$13ec$1@gioia.aioe.org> (permalink)
References <nstii2$8pl$1@gioia.aioe.org> <5d771b3c-0099-43eb-9373-c25f0d40e843@googlegroups.com> <nstsl8$s41$1@gioia.aioe.org> <87twctxbab.fsf@nightsong.com>

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On 2016-10-03 7:28 PM, Paul Rubin wrote:
> Walter Banks <walter@bytecraft.com> writes:
>> I guess what is modest hardware size. How big is needed to
>> accommodate most applications given that a user or compiler makes a
>> reasonable attempt to write good code.
>
> What do you mean by "most applications"?  Applications that run on
> workstations, mobile phones, internet servers etc. usually consume
> far more resources than the applications that run on stack processors
> from the Forth world.  Large Forth applications (there are a few)
> usually run on large machines (PC's etc.) so maybe aren't relevant to
> your question.
>
> Forth programs on stack machines or microcontrollers generally avoid
> complicated control flow and tend to use between a few and some
> dozens of stack cells, plus up to a few K of memory cells.  The GA144
> cpus iirc have 10 data stack levels (T and S registers plus an
> 8-level circular buffer) and 9 return stack levels (R register plus
> 8-level circular buffer) but they are very small cpus.  The Novix
> used off-chip stack memory with 256 elements for each stack, plus a
> few on-chip registers for the top levels.  The J1 appears to have 32
> levels for each stack: http://excamera.com/sphinx/fpga-j1.html
>
> If you can say the application area your processor is targeted at,
> you might get better advice.  If it's a general purpose processor
> that has to run mainstream software, you probably want a
> conventional architecture.
>
> The main reason other than recreation I can think of to make a stack
> CPU is you want some tiny sequencer in a little corner of a bigger
> FPGA application.  In that case you probably want to size the CPU to
> handle the surrounding application's specific requirements.  In the
> designs I've seen, you can choose the stack size by changing a couple
> lines of Verilog.
>

The application area is embedded systems in general. Like most
processors in this area processors tend to be used in application areas
rather than general purpose processors. The application area that it is
most likely to be used in is distributed control and instrumentation. It
is being implemented  with some configurations having multiprocessors.
The basic processor will be running at about 150Mips.

I have worked on quite a few of these developments over the last 30
years or so. We have prototypes running on fpga's. A lot of the
motivation of starting this thread is to get a different perspective on
stack usage and design outside of the metrics I have for C and asm based
applications used in similar area's of embedded systems.

I have been making a point of staying away from implementation languages
for a very specific reason. This processor will in all likelihood be
programed in a variant of C. As several people here have pointed out C
requires "..." which is true when you look at the C generic history.
Most certainly the open source tools have genetics going back to the
open C compiler tools. To make a point mapping locals on a stack frame
in a PDP-11 was probably a good way to implement locals on that platform
but as I have shown in many compilers not the only way. It doesn't have
to be that way C is a language that describes a problem and the compiler
writers (me) have to map the problem effectively on the target. I have
targeted C compilers to embedded processors, forth, functional languages
and even in one case a form of state machine. We have adapted the
language to support event driven applications. Forth has a much larger
component of implementation built into the actual application code.

This brings me back to the actual questions. My role in the tool
development of this project is more like a forth programmer than a C
programmer. The code creation trials and tribulations of this user group
are very close to the choices I am making writing the optimizer for the
code generator for this processor.

To address one last point you have made the underlying verilog or vhdl
implementing the ISA is flexible and easily changed I agree. We have
done that many times over the last year or so to understand the impact
of changes on code generation.

w..

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Thread

Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 08:22 -0400
  Re: Stack Sizes foxaudioresearch@gmail.com - 2016-10-03 07:00 -0700
    Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 11:14 -0400
      Re: Stack Sizes Bernd Linsel <bl1@gmx.com> - 2016-10-03 18:20 +0200
        Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-03 11:30 -0500
          Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-03 15:27 -0400
          Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 18:12 -0400
            Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-03 17:52 -0500
            Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-03 16:06 -0700
        Re: Stack Sizes Jan Coombs <jenfhaomndgfwutc@murmic.plus.com> - 2016-10-04 08:31 +0100
          Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-04 08:46 +0000
            Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 10:38 -0400
            Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-04 11:59 -0700
              Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-05 09:59 +0000
                Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-05 10:16 -0400
                Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-06 08:21 +0000
          Re: Stack Sizes minforth@arcor.de - 2016-10-04 05:00 -0700
          Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 08:49 -0400
      Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-03 16:28 -0700
        Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 10:36 -0400
          Re: Stack Sizes Rod Pemberton <NoHaveNotOne@zxdehrnyya.cam> - 2016-10-04 16:15 -0400
          Re: Stack Sizes Brad Eckert <hwfwguy@gmail.com> - 2016-11-09 09:56 -0800
            Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-11-12 09:15 -0500
    Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-03 10:35 -0500
    Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-10-11 01:01 +0000
  Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-03 10:21 -0400
    Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 11:06 -0400
      Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-03 15:22 -0400
        Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 18:04 -0400
    Re: Stack Sizes Hans Bezemer <the.beez.speaks@gmail.com> - 2016-10-04 20:46 +0200
      Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 15:40 -0400
        Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-05 12:26 -0700
          Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 15:44 -0500
            Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-05 16:32 -0700
              Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-05 20:01 -0400
                Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-07 07:39 +0000
              Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 20:36 -0500
                Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-05 21:28 -0700
          Re: Stack Sizes alex <alex@rivadpm.com> - 2016-10-05 22:07 +0100
            Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-06 00:05 -0700
            Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-06 02:17 -0500
      Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-04 19:27 -0400
        Re: Stack Sizes Hans Bezemer <the.beez.speaks@gmail.com> - 2016-10-05 18:58 +0200
          Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-05 13:17 -0400
            Re: Stack Sizes Hans Bezemer <the.beez.speaks@gmail.com> - 2016-10-22 12:35 +0200
          Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 12:18 -0500
            Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-05 16:07 -0400
              Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 15:50 -0500
                Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-05 17:36 -0400
                Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 17:14 -0500
                Re: Stack Sizes "Elizabeth D. Rather" <erather@forth.com> - 2016-10-05 14:48 -1000
                Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 20:49 -0500
  Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-03 16:32 +0000
  Re: Stack Sizes Chris Curl <ccurl609@gmail.com> - 2016-10-03 13:53 -0700
    Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 17:54 -0400
  Re: Stack Sizes Rod Pemberton <NoHaveNotOne@zxdehrnyya.cam> - 2016-10-03 23:40 -0400
    Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 11:30 -0400
  Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-03 21:47 -0700
    Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 11:22 -0400
      Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-04 11:44 -0700
        Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 15:53 -0400
          Re: Stack Sizes Rod Pemberton <NoHaveNotOne@zxdehrnyya.cam> - 2016-10-04 16:15 -0400
      Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-05 14:31 -0700
        Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-06 08:48 -0400
          Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-06 13:08 -0700
            Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-06 19:11 -0400
  Re: Stack Sizes jim.brakefield@ieee.org - 2016-10-06 12:08 -0700
    Re: Stack Sizes alex <alex@rivadpm.com> - 2016-10-06 21:47 +0100
    Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-06 19:05 -0400
    Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-06 21:57 -0400
      Re: Stack Sizes jim.brakefield@ieee.org - 2016-10-06 19:21 -0700
        Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-07 00:10 -0400
          Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-06 23:14 -0700
            Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-07 02:26 -0400
              Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-06 23:57 -0700
                Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-07 08:18 -0500
                Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-07 10:52 -0400
                Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-09 16:22 -0700
                Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-10 01:49 -0400
                Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-10 10:21 -0500
                Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-10 22:39 -0400
                Straight Forth Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-10 12:36 +0200
                Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-13 13:45 -0700
                Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-14 01:16 -0700
                Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-15 20:38 -0700
                Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-16 02:00 -0400
                Re: Straight Forth Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-16 18:38 -0700
                Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-16 22:27 -0400
                Re: Straight Forth Re: Stack Sizes Raimond Dragomir <raimond.dragomir@gmail.com> - 2016-10-16 21:14 -0700
                Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-17 00:35 -0400
                Re: Straight Forth Re: Stack Sizes Raimond Dragomir <raimond.dragomir@gmail.com> - 2016-10-16 23:31 -0700
                Re: Straight Forth Re: Stack Sizes "Elizabeth D. Rather" <erather@forth.com> - 2016-10-16 20:36 -1000
                Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-17 13:11 -0700
                Re: Straight Forth Re: Stack Sizes Rod Pemberton <NeedNotReplyHere@xrsevnneqk.cem> - 2016-10-17 19:14 -0400
                Re: Straight Forth Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-10-17 21:53 +0000
                Re: Straight Forth Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-17 16:54 -0700
                Re: Straight Forth Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-10-21 22:13 +0000
                Re: Straight Forth Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-21 17:46 -0700
                Re: Straight Forth Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-10-23 22:26 +0000
                Re: Straight Forth Re: Stack Sizes JUERGEN <epldfpga@aol.com> - 2016-10-24 09:13 -0700
                Re: Straight Forth Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-24 16:28 -0700
                Re: Straight Forth Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-24 17:20 -0700
                Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-24 22:23 -0400
                Re: Straight Forth Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-11-04 20:39 +0000
                Re: Straight Forth Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-16 22:42 -0700
                Re: Straight Forth Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-17 11:12 +0200
                Re: Straight Forth Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-17 09:20 -0700
                Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-17 19:11 -0400
                Re: Straight Forth Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-17 16:40 -0700
                Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-17 20:19 -0400
                Re: Straight Forth Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-17 17:25 -0700
                Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-17 20:50 -0400
                Re: Straight Forth Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-18 02:04 +0200
                Re: Straight Forth Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-18 06:13 +0000
                Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-16 15:21 -0700
                Re: Straight Forth Re: Stack Sizes Doug Hoffman <glidedog@gmail.com> - 2016-10-17 04:09 -0400
                Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-17 13:48 -0700
                Re: Straight Forth Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-18 02:12 +0200
                Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-18 00:35 -0700
                Re: Straight Forth Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-18 12:53 +0200
                Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-18 12:12 -0700
                Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-07 16:53 +0000
                Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-09 08:34 -0500
                Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-09 16:03 +0000
                Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-10 03:25 -0500
                Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-10 10:29 -0500
                Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-11 05:19 -0500
                Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-10 14:41 +0000
                Re: Stack Sizes Lars Brinkhoff <lars.spam@nocrew.org> - 2016-10-10 20:23 +0200
                Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-11 05:16 -0500
                Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-12 12:54 +0000
                Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-12 18:27 +0200
                Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-12 17:06 +0000
                Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-12 13:01 -0500
                Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-12 17:07 -0400
                Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-13 03:18 +0200
                Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-14 14:26 -0400
                Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-12 20:30 -0700
                Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-13 15:52 +0000
                Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-13 15:05 -0700
                Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-14 03:08 -0500
                Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-14 14:41 -0400
                Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-07 12:33 -0500
                Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-08 01:12 -0400
              Re: Stack Sizes Rod Pemberton <NeedNotReplyHere@xrsevnneqk.cem> - 2016-10-07 23:05 -0400
                Re: Stack Sizes jim.brakefield@ieee.org - 2016-10-07 21:56 -0700
                Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-08 07:23 -0400
                Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-11 22:39 -0700
            Re: Stack Sizes Lars Brinkhoff <lars.spam@nocrew.org> - 2016-10-07 08:21 +0200
            Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-07 09:22 +0200
              Re: Stack Sizes Lars Brinkhoff <lars.spam@nocrew.org> - 2016-10-07 09:35 +0200
                Re: Stack Sizes jim.brakefield@ieee.org - 2016-10-07 10:51 -0700
                Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-07 13:21 -0500
                Re: Stack Sizes Lars Brinkhoff <lars.spam@nocrew.org> - 2016-10-07 20:40 +0200
                Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-07 20:53 +0200
            Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-07 07:35 +0000
              Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-07 01:09 -0700
                Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-07 15:59 +0000
                Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-10-17 22:05 +0000

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