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Re: Forth-94 vs. Forth-2012 FP data (long)

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Anton Ertl wrote:
> "HAA" <someone@microsoft.com> writes:
> >How about this for an 'empirical' check.  Write a real-world application
> >for which hardware f/p is not available.  Implement it using combined
> >and separate stack f/p.  Compare the performance and memory used.
> >Expect to see much difference?  Neither do I.
>
> I didn't expect it for the matrix multiplication case, but I actually
> measured it and found a difference, and found an explanation for the
> difference.  Maybe you should actually read the whole posting before
> replying.

Performance has never been the sole criteria by which TC's made
decisions, so let's ditch that as a reason for excluding common
stacks systems from 2012.

What's left is the alleged difficulty ANS imposed on f/p programmers.
It's been claimed by you - and now by 2012 (C.7.2) - that ANS required
programmers to either code for a common stack, or to declare a
dependency on a separate stack.  There is in fact no such stipulation
in ANS - quite the opposite.  Sections or parts thereof in ANS which
dispelled such allegations have been either removed or reworded by
2012, leaving the reader to believe 2012 has given them something
they didn't, or couldn't, have with ANS.  Here's what ANS said
(emphasis added):

12.3.3

    "BY DEFAULT the floating-point stack SHALL be separate from
    the data and return stacks.
    A program MAY determine whether floating-point numbers are
    kept on the data stack by passing the string "FLOATING-STACK"
    to ENVIRONMENT?."

A.12

    "Floating-point stack: BY DEFAULT the floating-point stack IS
    separate from the data and return stacks; HOWEVER, an
    implementation MAY keep floating-point numbers on the data
    stack."

ANS left no doubt "separate stack" is the "default" and common stack
was an option for implementers who wanted or needed it.  ANS went to
pains to over this e.g. FDEPTH refers to the "default separate floating-
point stack".

Is a separate stack program required to declare a dependency on a
separate stack?  Logically it would be redundant since ANS stated
separate stack is the default.  In any case no such dependency is listed:

12.4.2 Program documentation

12.4.2.1 Environmental dependencies
      - requiring the floating-point stack to be larger than six items
     (12.3.3 Floating-point stack).

12.4.2.2 Other program documentation
      - no additional requirements.

Had 200x TC found ANS' statements ambiguous (hard to believe had they
actually read ANS), could they have rewritten them without having to remove
common stack systems?  I don't see why not.  So why were common stack
systems excluded from 2012?  I believe the answer can be found here:

    "Whilst every sane Forth has a separate floating-point stack,
    it is not strictly required; an ANS Forth system could theoretically
    keep floating-point numbers on the data stack.  As an additional
    difficulty, you don't know how many cells a floating-point number
    takes. It is reportedly possible to write words in a way that they
    work also for a unified stack model, but we do not recommend
    trying it."

That statement, which has appeared in gforth's documentation since
at least 1998, presents an opinion.  It is clear the author holds a view
that is intolerant of combined stack f/p and of those who implement it.

> If we did not put common practice in the standard, we would
> not be doing our job.

Removing common stack implementations with no technical justification.
Propagating opinion and statements known to be fallacious, or at the
very least, contentious.  Including these in a Standard document as fact.
Is this the job of a responsible technical committee which claims to
speak on behalf of Forth users?

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Thread

Forth-94 vs. Forth-2012 FP data (long) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-13 07:34 +0000
  Re: Forth-94 vs. Forth-2012 FP data (long) pahihu <pahihu@gmail.com> - 2017-05-13 11:16 -0700
    Re: Forth-94 vs. Forth-2012 FP data (long) pahihu <pahihu@gmail.com> - 2017-05-13 11:49 -0700
      Re: Forth-94 vs. Forth-2012 FP data (long) pahihu <pahihu@gmail.com> - 2017-05-13 13:38 -0700
        Re: Forth-94 vs. Forth-2012 FP data (long) mhx@iae.nl - 2017-05-13 15:08 -0700
          Re: Forth-94 vs. Forth-2012 FP data (long) pahihu <pahihu@gmail.com> - 2017-05-14 00:51 -0700
          Re: Forth-94 vs. Forth-2012 FP data (long) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-14 07:32 +0000
            Re: Forth-94 vs. Forth-2012 FP data (long) mhx@iae.nl - 2017-05-14 02:46 -0700
              Re: Forth-94 vs. Forth-2012 FP data (long) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-14 14:57 +0000
                Re: Forth-94 vs. Forth-2012 FP data (long) krishna.myneni@ccreweb.org - 2017-05-15 19:11 -0700
    Re: Forth-94 vs. Forth-2012 FP data (long) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-14 08:14 +0000
  Re: Forth-94 vs. Forth-2012 FP data (long) Paul Rubin <no.email@nospam.invalid> - 2017-05-13 15:58 -0700
    Re: Forth-94 vs. Forth-2012 FP data (long) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-14 07:01 +0000
  Re: Forth-94 vs. Forth-2012 FP data (long) krishna.myneni@ccreweb.org - 2017-05-14 19:04 -0700
    Re: Forth-94 vs. Forth-2012 FP data (long) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-15 06:10 +0000
      Re: Forth-94 vs. Forth-2012 FP data (long) krishna.myneni@ccreweb.org - 2017-05-15 01:49 -0700
        Re: Forth-94 vs. Forth-2012 FP data (long) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-15 14:33 +0000
  Re: Forth-94 vs. Forth-2012 FP data (long) "HAA" <someone@microsoft.com> - 2017-05-15 13:44 +1000
    Re: Forth-94 vs. Forth-2012 FP data (long) Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-05-15 04:43 -0500
    Re: Forth-94 vs. Forth-2012 FP data (long) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-15 15:03 +0000
      Re: Forth-94 vs. Forth-2012 FP data (long) "HAA" <someone@microsoft.com> - 2017-05-17 00:10 +1000
  Re: Forth-94 vs. Forth-2012 FP data (long) pahihu <pahihu@gmail.com> - 2017-05-16 09:04 -0700
    Re: Forth-94 vs. Forth-2012 FP data (long) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-17 15:54 +0000
      Re: Forth-94 vs. Forth-2012 FP data (long) mhx@iae.nl - 2017-05-17 10:29 -0700
      Re: Forth-94 vs. Forth-2012 FP data (long) pahihu <pahihu@gmail.com> - 2017-05-17 23:53 -0700
        Re: Forth-94 vs. Forth-2012 FP data (long) pahihu <pahihu@gmail.com> - 2017-05-19 02:34 -0700
  Re: Forth-94 vs. Forth-2012 FP data (long) Joel Rees <joel.rees@gmail.com> - 2017-05-16 22:48 -0700
    Re: Forth-94 vs. Forth-2012 FP data (long) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-17 06:51 +0000
      Re: Forth-94 vs. Forth-2012 FP data (long) Joel Rees <joel.rees@gmail.com> - 2017-05-17 09:29 -0700
    Re: Forth-94 vs. Forth-2012 FP data (long) stephen@mpeforth.com (Stephen Pelc) - 2017-05-17 11:07 +0000
      Re: Forth-94 vs. Forth-2012 FP data (long) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-17 15:02 +0000

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