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Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth

From "Alex McDonald" <blog@rivadpm.com>
Newsgroups comp.lang.forth
Subject Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth
Date 2015-03-19 09:43 +0000
Organization A noiseless patient Spider
Message-ID <mee5nb$9t5$1@dont-email.me> (permalink)
References <09b0d52b-de4f-4805-9cc1-fc1cc0499ac3@googlegroups.com> <85lhiuioif.fsf@junk.nocrew.org> <op.xvptc4bjwa0t4m@localhost> <med394$e5d$1@dont-email.me> <op.xvp3ihupwa0t4m@localhost>

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on 19/03/2015 02:21:41, "Rod Pemberton" wrote:
> On Wed, 18 Mar 2015 19:56:06 -0400, Alex McDonald <blog@rivadpm.com>
> > wrote:
>> on 18/03/2015 22:42:31, "Rod Pemberton" wrote:
> > wrote:
>>> On Wed, 18 Mar 2015 06:33:12 -0400, Lars Brinkhoff
> > wrote:
>>> <lars.spam@nocrew.org> wrote:
> > wrote:
>>>> JUERGEN <epldfpga@aol.com> wrote:
> wrote:
> 
>>>>>> But for a project we would like to have a list of words that
>>>>>> fit into 4 bits - so 16 words max to be used.
>>>>>> Any good suggestions?
>>>>
>>>> My suggestion might be:
>>>>
>>>> Definitions:          dodoes exit
>>>> Control flow:         0branch
>>>> Literals:             (literal)
>>>> Memory access:        ! @ c! c@
>>>> Aritmetic/logic:      + nand
>>>> Return stack:         >r r>
>>>>
>>>> Of course, c! and c@ may be optional if you're content with cell-sized
>>>> characters.  I experimented with removing 0branch, (literal), >r, and
>>>> r>, but the resulting system became orders of magnitude slower.
>>>>
>>>> Add to this some of DUP, SWAP, OVER, DROP, 0<, etc.  Or maybe you need
>>>> access to the stack pointers: SP@, SP!, RP@, RP!.
>>>
>>> As my other post indicates, it's going to be hard to live with only
>>> 16 primitive (or low-level) words maximum.
>>>
>>> So, he might be interested in a shift-state. E.g., perhaps an
>>> instruction could be used to shift between two sets of 16 words. That
>>> would provide a total of 30 words, not including the shift word in
>>> both states/sets.
>>>
>>
>> Shifting state has its own problems. A word expects a certain state
>> for the tokens it will execute.
> 
> Only when the primitives (low-level words) are executed does the state
> need to be correct or correctly switched.
> 

Every word hits bottom at some point, and the state has to be correct.
You either remember the state in a stack, or you use one of your 8
opcodes in both sets to switch in and out on every instruction that is in
the second set.
 
> E.g., for a word in the first set you do nothing.  For a word in the
> second set, you could switch to the second state, execute a primitive
> from the second set, switch back to the first.  Each instruction in
> the second set would be wrapped with the switch words.  Let's say the
> zero'th instruction is the switch word.  To execute one instruction
> from the first set (3rd) and one instruction from the second set
> (4th):
> 
> set1_3rd set1_0th(switch) set2_4th set2_0th(switch)
> 
> In pure Forth it would look something like the following if SWAP
> is in set1 and >R is in set2:
> 
> SWAP SWITCH >R SWITCH

SWITCH needs to be in set 1 and set 2, and now we have a 3 nibble opcode
with only 7 opcodes in the encoding space...

> 
> Since these are primitives, the SWITCH wrapper can be part of
> the low-level code for each set2 instruction.

You've now got a prefix for a 2 nibble opcode; it's no longer shift in
and out.

> 
> Obviously, you'd attempt to put less frequently used words in the
> second set due to the overhead.  The advantage here is there is no
> need to decode instructions based on bits as your (snipped) example
> would need.  

Any encoding that uses regular bit patterns, such as the UTF example, can
be table decoded at exactly the same cost per nibble or byte.


> Zero is also easy to detect.  Philip Koopman's or
> Anton Ertl's instruction frequencies could be used to help decide
> which set is which.
> 
> 
> Rod Pemberton
>

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What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth JUERGEN <epldfpga@aol.com> - 2015-03-17 12:47 -0700
  Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2015-03-17 22:29 +0100
    Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-03-18 10:59 +0000
      Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Lars Brinkhoff <lars.spam@nocrew.org> - 2015-03-18 12:04 +0100
        Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-03-18 11:19 +0000
          Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Lars Brinkhoff <lars.spam@nocrew.org> - 2015-03-18 12:39 +0100
            Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Elizabeth D. Rather" <erather@forth.com> - 2015-03-18 08:05 -1000
              Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-03-18 18:34 +0000
              Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Lars Brinkhoff <lars.spam@nocrew.org> - 2015-03-18 20:05 +0100
  Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-03-17 19:11 -0400
    Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Rod Pemberton" <bork@lllljunkqwer.cpm> - 2015-03-19 00:28 -0400
      Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth rickman <gnuarm@gmail.com> - 2015-03-20 01:00 -0400
  Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Lars Brinkhoff <lars.spam@nocrew.org> - 2015-03-18 11:33 +0100
    Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2015-03-18 22:15 +0100
      Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Lars Brinkhoff <lars.spam@nocrew.org> - 2015-03-19 07:53 +0100
      Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth visualforth@rocketmail.com - 2015-03-19 17:17 -0700
      Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth rickman <gnuarm@gmail.com> - 2015-03-20 01:01 -0400
    Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Rod Pemberton" <bork@lllljunkqwer.cpm> - 2015-03-18 18:42 -0400
      Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Alex McDonald" <blog@rivadpm.com> - 2015-03-18 23:56 +0000
        Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2015-03-19 02:46 +0100
          Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Alex McDonald" <blog@rivadpm.com> - 2015-03-19 09:27 +0000
        Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Rod Pemberton" <bork@lllljunkqwer.cpm> - 2015-03-18 22:21 -0400
          Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Alex McDonald" <blog@rivadpm.com> - 2015-03-19 09:43 +0000
            Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Rod Pemberton" <bork@lllljunkqwer.cpm> - 2015-03-20 02:09 -0400
              Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Alex McDonald" <blog@rivadpm.com> - 2015-03-20 15:41 +0000
                Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Rod Pemberton" <bork@lllljunkqwer.cpm> - 2015-03-29 16:23 -0400
                Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth rickman <gnuarm@gmail.com> - 2015-03-29 16:43 -0400
                Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Alex McDonald" <blog@rivadpm.com> - 2015-03-29 22:53 +0100
      Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Lars Brinkhoff <lars.spam@nocrew.org> - 2015-03-19 08:00 +0100
        Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth "Rod Pemberton" <bork@lllljunkqwer.cpm> - 2015-03-20 02:09 -0400
    Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Lars Brinkhoff <lars.spam@nocrew.org> - 2015-03-20 14:43 +0100
      ...Tiny targets Matthias Koch <matthias.koch@hot.uni-hannover.de> - 2015-03-23 15:26 +0100
        Re: ...Tiny targets Paul Rubin <no.email@nospam.invalid> - 2015-03-23 10:39 -0700
        Re: ...Tiny targets JUERGEN <epldfpga@aol.com> - 2015-03-24 01:18 -0700
          Re: ...Tiny targets Paul Rubin <no.email@nospam.invalid> - 2015-03-24 17:45 -0700
            Re: ...Tiny targets JUERGEN <epldfpga@aol.com> - 2015-03-25 00:08 -0700
              Re: ...Tiny targets Paul Rubin <no.email@nospam.invalid> - 2015-03-25 00:43 -0700
                Re: ...Tiny targets Gary Bergstrom <forthprgrmr@gmail.com> - 2015-03-25 07:07 -0700
                Re: ...Tiny targets Paul Rubin <no.email@nospam.invalid> - 2015-03-25 08:06 -0700
                Re: ...Tiny targets rickman <gnuarm@gmail.com> - 2015-03-25 15:19 -0400
                Re: ...Tiny targets Paul Rubin <no.email@nospam.invalid> - 2015-03-25 12:39 -0700
                Re: ...Tiny targets Bernd Paysan <bernd.paysan@gmx.de> - 2015-03-25 20:42 +0100
                Re: ...Tiny targets rickman <gnuarm@gmail.com> - 2015-03-25 16:41 -0400
                Re: ...Tiny targets hughaguilar96@gmail.com - 2015-03-25 22:32 -0700
                Re: ...Tiny targets "Alex McDonald" <blog@rivadpm.com> - 2015-03-26 09:35 +0000
                Re: ...Tiny targets Ron Aaron <rambamist@gmail.com> - 2015-03-26 14:52 +0200
                Re: ...Tiny targets rickman <gnuarm@gmail.com> - 2015-03-27 16:12 -0400
                Re: ...Tiny targets albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-03-26 13:00 +0000
                Re: ...Tiny targets anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-03-26 11:58 +0000
                Re: ...Tiny targets JUERGEN <epldfpga@aol.com> - 2015-03-25 07:10 -0700
                Re: ...Tiny targets JUERGEN <epldfpga@aol.com> - 2015-03-25 07:16 -0700
            Re: ...Tiny targets Matthias Koch <matthias.koch@hot.uni-hannover.de> - 2015-03-27 13:01 +0100
  Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Gary Bergstrom <forthprgrmr@gmail.com> - 2015-03-18 06:45 -0700
    Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth JUERGEN <epldfpga@aol.com> - 2015-03-18 08:57 -0700
      Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth Lars Brinkhoff <lars.spam@nocrew.org> - 2015-03-18 20:09 +0100
    Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth JUERGEN <epldfpga@aol.com> - 2015-03-18 08:59 -0700
    Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth hughaguilar96@gmail.com - 2015-03-20 21:47 -0700
      Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth JUERGEN <epldfpga@aol.com> - 2015-03-21 02:30 -0700
        Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth hughaguilar96@gmail.com - 2015-03-21 17:52 -0700
          Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth JUERGEN <epldfpga@aol.com> - 2015-03-22 01:27 -0700
            Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth hughaguilar96@gmail.com - 2015-03-22 13:15 -0700
            Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth hughaguilar96@gmail.com - 2015-03-22 13:47 -0700
            Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth rickman <gnuarm@gmail.com> - 2015-03-22 18:39 -0400
            Re: What is the minimum Word set you could live with to have a (limping) Beginner's ANS Forth hughaguilar96@gmail.com - 2015-03-22 16:32 -0700
            Re: What is the minimum Word set you could live with to have a(limping) Beginner's ANS Forth "WJ" <w_a_x_man@yahoo.com> - 2015-03-26 06:35 +0000
              Re: What is the minimum Word set you could live with to have a(limping) Beginner's ANS Forth rickman <gnuarm@gmail.com> - 2015-03-27 15:55 -0400
                Re: What is the minimum Word set you could live with to have a(limping) Beginner's ANS Forth "Rod Pemberton" <bork@lllljunkqwer.cpm> - 2015-03-28 03:36 -0400
          Re: What is the minimum Word set you could live with to have a(limping) Beginner's ANS Forth "WJ" <w_a_x_man@yahoo.com> - 2015-03-26 06:34 +0000

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